Answers to Worksheets



Answers to Worksheets

Contents

Chapter 1 — Introducing science

Chapter 2 — Staying alive

Chapter 3 — Changing materials

Chapter 4 — Big changes

Chapter 5 — Safety first

Chapter 6 — Tomorrow’s weather

Chapter 7 — Use it again

Chapter 8 — Water

Chapter 9 — Energy converters

Chapter 10 — Under the skin

Chapter 1 — Introducing science

Worksheet 1 — What is science?

9

|Type of scientist |Area of study |

|Astronomer |Heavenly bodies; including their movements, positions, distances and sizes. |

|Chemist |The composition and properties of substances. |

|Botanist |Plant life. |

|Zoologist |Animal life. |

|Physicist |Laws and properties of matter and energy. |

|Pathologist |The origin, nature and course of diseases. |

10 A herpetologist studies reptiles and amphibians.

11 A herpetologist is part of the group ‘zoologists’.

12 An ecologist studies relationships between organisms (living things) and their environments.

13 An ecologist would require some knowledge of botany, zoology and geology and well as some pathology and chemistry.

Worksheet 2 — Galileo Galilei

1 It is 443 years since Galileo was born.

2 Many people are making significant contributions to their specialist area. They may be remembered in their own area but not by the general population. Some very significant discoveries – such as the structure of DNA – may mean that the names of Watson and Crick are remembered far into the future. Many discoveries today are made by teams of people rather than by one individual.

3 Telescope

5 He did not agree with the ideas held by the Church at the time. In Galileo’s time it was the Church that controlled knowledge and decided what people should be told. Galileo refused to keep quiet about his ideas so he broke the laws of the Church. The Church authorities therefore placed him under house arrest for the rest of his life.

6 The view at the time was that the Earth was the centre of the system and the Sun and the planets that were known circled round the Earth. This was the ‘geocentric’ view of the universe. Galileo’s idea was that the Sun was the centre of the universe and the Earth was one of the planets that circled round the Sun. This is a ‘heliocentric’ view of the universe.

Worksheet 3 — How observant are you?

1

[pic]

The diameter of a 10c coin is 2.3 cm.

4 Differences

▪ Level of water in the container being filled.

▪ Different pattern of writing and pictures on the pages of the text book.

▪ Label on container changes from salt to sugar.

▪ The cap on the container is a different colour.

▪ Only one student in the background.

▪ Change to poster on the wall.

▪ Student pouring the water has a different shirt collar.

▪ The student watching at the front has shorter hair.

▪ There is no second book underneath the text book.

▪ The handle of the jug is different.

▪ The spoon is in a different position.

▪

5, 6

|Sense |Observations |Examples of uses |

|Hearing |Sounds in our environment |Recognise sounds that are different that may alert us to danger. |

| | |People approaching. |

| | |Sirens or other alarms. |

| | |Tone of voice – recognise anger, teasing, sadness. |

|Taste |Taste of food. |Recognise food that has gone bad and may make us sick. |

| | |Distinguish between foods we like and dislike. |

| | |Learn new tastes of foods that are safe to eat. |

| | |Distinguish between things that can look the same such as salt and sugar. |

|Touch |Many aspects of our |Provides information about the things with which your body comes in contact. |

| |environment. |Recognise hot and cold, rough and smooth, wet and dry, slimy, ridged, soft, hard, angular, |

| | |rounded. |

| | |People who are blind use their fingertips to read Braille by feeling the patterns of raised dots|

| | |on their paper. |

| | |We use our sense of touch to find our way in the dark. |

|Smell |Odours in the environment |The smell of many chemicals — distinguish between ones that are safe and those that are harmful.|

| | |Smell food and recognise the difference between foods we like and those we dislike. |

| | |Smell food that has gone bad. |

| | |Get pleasure from scents we like such as flowers or perfume. |

| | |Alerted to danger — smell of burning. |

Worksheet 4 — Quantitatively speaking

1 Time will go on the horizontal axis because it is the independent variable — the one that is changed by the experimenter.

2 Temperature will go on the vertical axis. It is the dependent variable.

Worksheet 5 — What happened here?

1

|Observation |Inference |

|The candle has wax drips on the side. |It must have been lit last night. |

|The clouds are black. |It is going to rain. |

|The glass is broken. |A ball must have gone through the window. |

|The lights have gone out. |There must be a power cut. |

|They are on the top of the competition ladder. |The sharks will win on Saturday |

2, 3, 4

|Observation |Inference |Other information required |

|Window of jeweller’s is broken |There has been a robbery. |Window broken from the outside. |

| | |No other possible cause for the breakage. |

| | |There is no fault in the alarm system or other reason |

| | |for the alarm to be triggered. |

| | |Jewellery missing from the window display. |

|Alarm in the shop is ringing | | |

|Person in the RH car is wearing a balaclava. |Driver is the robber. |Fingerprints found on the window or on fittings within |

| | |the shop front. |

| | |Jewellery in the car. |

|Skid marks on the road. |LH car tried to stop. |Statement of events from the driver or other witnesses.|

|Car on right should have given way. |Driver not thinking, driving too fast |Statement from the ‘robber’. |

| |trying to get away from the robbery. |Statements from other witnesses. |

Worksheet 7 — Professor Fred Hollows

1 An ophthalmologist studies the eyes.

2 Bacteria.

3 The eyelids to turn inwards and the eyelashes scratch the surface of the eye.

4 Trachoma is found in parts of the world without adequate access to water and sanitation.

5 They do not have the same access to medical facilities.

6 Cataract.

7 In developing countries there is a lack of medical resources and the cost of treatment is high.

8 IOL stand for intraocular lens.

a Intra. The prefix means within.

b Ocular. Ocular is an adjective that describes things related to the eye.

c Lens.

10 They are used to replace the damaged lens of the eye.

11 The Fred Hollows Foundation is an organisation established with the aim of reducing the cost of eye health care and treatment in developing countries.

Worksheet 8 — Key terms

1 geologists

2 pharmacist

3 Observation

4 Inferences; inference

5 Fair; Independent variable; Dependent variable.

6 ophthalmologist; trachoma; cataract; Cataract; intraocular lens

Chapter 2 — Staying alive

Worksheet 1 — Thinking about staying alive

4 Humans are living things and therefore display all the characteristics of living things.

They are different from other living things because of their intelligence. Through use of intelligence they have been able to control their environment to some extent. For example:

▪ Humans grow food and distribute it to where people are living therefore individuals do not have to hunt or gather their own food.

▪ There are laws controlling behaviour and interactions between groups therefore these humans do not have to fight for territory or places to build homes.

▪ Humans have controlled many diseases.

Worksheet 2 — You can’t catch me!

1 Somebody who is a faster runner or able to anticipate where the prey might go may be able to catch more prey.

2 It should become more difficult for the predators to catch their prey as the game progresses.

3 The numbers of prey competing for the hiding places decreases therefore a larger percentage of the prey are able to hide.

6 If a prey animal remains close to its den then it can return there and hide more easily if a predator comes along.

Different examples

• If the number of predators was increased the numbers of prey should reduce more quickly. Some prey should still be able to escape the predators.

• If the number of prey was decreased the predators would find it more difficult to catch their prey.

• If the number of hiding places was decreased more of the prey would be exposed and in danger of being captured by the predators.

• If the area over which the game was conducted increased the predators would have to run further and would become tired more easily. This may be an advantage to the prey as long as they did not have to run further to find hiding places.

• If the prey walked and the predators ran the predators should be able to catch the prey more easily.

• If the predators walked and the prey ran the prey should be able to escape from the predators more easily.

|Ways model is similar to real life |Ways model is different to real life. |

|There are more prey animals than predators. |The difference in numbers between prey and predator should be much |

|There are hiding places for the prey. |greater. |

|Once the predator has caught the prey they do not hunt again for a|There should be a lot more potential hiding places. |

|time. |Prey animals are often a lot smaller than the predator. |

| |The surviving prey would have babies adding to the numbers of available |

| |prey. |

| |The distances involved could be a lot larger. |

| |There would not be a time limit for the prey hiding. |

| |The time that the predators are not hunting after catching prey is |

| |shorter. |

Worksheet 5 — Predators of the ocean.

1 Sharks.

2 Cartilage is lighter than bone. It therefore takes less energy to move through the water.

3 a On the skin.

b Sharks can swim through the water causing hardly a ripple. The prey animals do not know they are coming.

4 They eat different types of food. The shape of the teeth is an adaptation to the types of food animals eat.

5 Once the two sets of teeth were damaged or lost the animals would not be able to capture its food and would starve to death.

6 It lives on the ocean floor waiting for prey rather than swimming through the water and hunting for prey. The colour of the skin is camouflage in its living place.

Research

Not all sharks are predators. Some are filter feeders meaning that they strain their food out of the water. Others are herbivores.

Worksheet 6 — Food chains of the ocean

Possible food chains include:

Phytoplankton → krill → humpback whale

Phytoplankton → shrimp → penguin → killer whale

Phytoplankton → squid → penguin → killer whale

Phytoplankton → squid → seal → killer whale

Phytoplankton → small fish → penguin → killer whale

Phytoplankton → small fish → large fish → penguin → killer whale

A possible food web

[pic]

Worksheet 7 — Insects — a very important group of animals

1 Arthropods.

2 Insects are found in every environment of the world except for the frozen worlds of the north and south poles and near active volcanoes.

3 Possible answers include:

o Mosquitoes carry diseases such as malaria, Murray Valley encephalitis and Ross River Virus.

o Termites damage buildings.

o Locusts destroy crops.

o Weevils spoil stores of grain.

4 Possible answers include:

o Bees, wasps, butterflies and moths pollinate flowering plants.

o Bees make honey and wax.

o Silk worms (the larval form of a moth) make silk fibres.

o Maggots (the larvae of blowflies) can be used to treat septic and gangrenous wounds.

5 Indigenous Australians used insects from their environment as food, medicine, and as part of their cultural beliefs. Using insects as food was probably the most important use.

Chapter 3 — Changing materials

Worksheet 1 — What do I know about changes?

Examples

|Changes |Reversible/not reversible |Causes of change |New substances being produced |

|Cereal becomes soggy when milk is |Reversible |Liquid absorbed |No new substance |

|poured over it. | | | |

|Bread is toasted. |Not reversible |Burning |Bread is being burnt and will |

| | | |eventually produce carbon. |

|Butter spread on toast. |Reversible |Change of shape of butter |No new substance |

|Vegemite spread on toast. |Reversible |Change of shape of vegemite |No new substance |

|Water boiled. |Reversible |Heating |No new substance |

|Tea/coffee made. |Reversible |Dissolving |No new substance |

|Egg boiled. |Not reversible |Cooking |The chemicals in the egg are being |

| | | |changed. |

|Make chocolate milk. |Reversible |Dissolving |No new substance |

Worksheet 2 — Dissolving.

1 To investigate dissolving.

2 Only one substance in each container.

Same amount of water in each container.

Same amount of each substance added to their containers.

Each container stirred for the same length of time.

3 The white sugar, brown sugar and salt should dissolve. The flour, chalk and sand are insoluble.

4

|Solid |Observation |Soluble/insoluble |

|Brown sugar |Disappeared into the water. The water was a light brown |soluble |

| |colour. | |

|Sand |Most of the sand sank to the bottom of the container. |insoluble |

|White sugar |Disappeared into the water. |soluble |

| |Could smell the sweet sugary smell in the water. | |

|Ground up chalk |Some of the chalk floated on the surface of the water. Some |insoluble |

| |of it floated in the water making it cloudy. A little sank to| |

| |the bottom. | |

|Flour |Some of the flour floated on the top of the water and some |insoluble |

| |mixed through the water making it cloudy. | |

|Salt |Disappeared into the water. |soluble |

5 I know that brown sugar, white sugar and salt dissolved in water because they could not be seen in the water, the water was still clear.

If a substance stays on the bottom or floats on the top when mixed with water it is not soluble.

8 Possible suggestions

▪ Smell or taste the water. (Alert students to the safety factors associated with tasting an unknown substance.)

▪ Evaporate the water and see if the dissolved substance is left behind.

▪ Some dissolved substances (such as the brown sugar) colour the water indicating that something is in the water.

9 Possible suggestion — Evaporate off the liquid either by heating or by leaving in a warm, sunny area.

Worksheet 3 — Chemical change

1 To investigate a chemical change.

2 The mixture inside the bottle fizzes producing a lot of bubbles.

The balloon starts to fill and stands upright.

3 The fizzing suggests a gas being given off that was not there before. Therefore this is a chemical change.

4 When bicarbonate of soda is added to vinegar a chemical change takes place. The evidence of a chemical change is a gas being produced.

6 The equipment was sealed therefore there was no way that anything could be added.

7 The equipment was sealed therefore nothing should have been lost to the system. However, it is possible that some of the gas escaped because it was under pressure.

8 Nothing was added to or lost from the system. Therefore it was only the materials already in the system that caused the change.

9 A similar reaction to the one in the experiment occurs. Instead of reacting with acetic acid, the bicarbonate of soda reacts with the tartaric acid to produce a gas. The gas bubbles are trapped in the cake mixture. As the cake is cooked (heated) in the oven the gas expands making the mixture rise and leaving the holes in the cake when the cooking is finished.

10 The dry ingredients do not react. They have to be dissolved before they react.

Worksheet 4 — Chemical or physical change?

1 Physical changes are changes that usually can be reversed and where no new substance is formed.

2 Chemical changes are changes that produce new substances and cannot easily be reversed.

3 New substance formed

Bubbles form (gas produced)

Permanent colour change

Heat and/or light produced

4

|Example of change |Physical /chemical|Reasons |

|Dissolving sugar in a cup of hot coffee. |Physical |The sugar could be recovered from the coffee. There is no new |

| | |substance. |

|Burning fallen leaves. |Chemical |The leaves have changed to ash and the gases given off in burning |

| | |(carbon dioxide). The ash cannot be turned back into leaves. |

|Melting wax. |Physical |The wax hardens and is chemically unchanged. |

|Making yoghurt from milk. |Chemical |The flavour of the milk has changed indicating that a new substance |

| | |has been formed. Yoghurt cannot be made back into milk. |

|Paint drying. |Chemical |Chemical reactions occur as the paint dries. Adding water (or |

| | |another solvent) cannot return the paint to its original form. |

|Breaking an egg. |Physical |Although the egg cannot be repaired, there is no new substance. |

|Boiling an egg. |Chemical |The egg white and yolk both change colour and texture. New |

| | |substances are formed. |

|Letting off fireworks. |Chemical |Light and heat are given off. The explosive noise also indicated |

| | |that a chemical reaction has occurred. The original chemicals in the|

| | |fireworks cannot be recovered. |

Worksheet 5 — Traditional ways of changing materials

1 • The seeds contain poisons. Soaking them in water removes the soluble poisons.

• The seeds are pounded into a flour and made into cakes. The cakes were then roasted.

• Roasting destroyed the remaining poisons.

2 The flour can be used to make cakes, bread and biscuits. It is more versatile than the roots or seed would be.

Grater – use a rough stone or chip parts of the stone away to create a rough surface.

Grinding stone – wear away one stone using a harder stone until a hollow is formed.

3 • Very hard woods were used to make spear heads.

• Spear tips could be made even harder by burning them in a fire and then scraping off the charred surface to form the point.

4 Remove strips bark from the red leaf fig → scrape away the outer bark to leave the soft, moist inner bark → hand roll strips to form string → twist strands together to make thicker string.

5 String was used to attach spear points and axe heads to the shafts. It could also be woven into traps for fish and birds.

6

|Change |Chemical or physical |

|Soaking seeds of Moreton Bay Chestnut |Physical – dissolving |

|Pounding seeds of Moreton Bay Chestnut |Physical |

|Roasting seeds of Moreton Bay Chestnut |Chemical |

|Hardening spear heads |Chemical |

|Making string |Physical |

|Making grinding stone |Physical |

|Making grater |Physical |

Worksheet 6 — Stone to iron

1 It could be chipped to create a sharp edge.

2 a Gold does not interact with other substances and is found as pure gold in the ground.

b For jewellery and as decoration .

c It is too soft and will not keep a sharp edge.

3 a harder

b Although it is harder than gold it is still not hard enough to keep a sharp edge.

4 a Copper and tin melted together.

b It can hold a sharp edge and it melts at a lower temperature than other metals.

5 It is plentiful and therefore much cheaper than bronze.

6 Making bells and cymbals; saxophones. Widely used for moulded sculpture. Mixed with other metals it is used for bearings, clips, electrical connectors and springs.

7 a A mould would be made. Molten bronze would be poured into the mould and left to harden. The mould would then be removed.

b A copper arrow head could be beaten into shape.

Worksheet 7 — Rusting

1 To investigate the effects of different environmental conditions on the rusting of iron.

2 Ensuring that the salt concentration is the same in all the relevant containers.

Same number of screws added to each container.

Equal amounts of water or salt water added to the relevant containers.

All containers left undisturbed for the same length of time.

3 Dry screws should rust least or not at all, ones in water should rust more and the ones in salt water should rust most.

Galvanised screws and stainless screws should not rust.

5 The answer should be yes. However, if the atmosphere is very humid, there could be enough moisture in the air to cause some rusting.

6 Yes

7 The screws that were neither galvanised not stainless steel.

8 If the galvanising provides a complete coat there should be no rusting. However if the galvanising is not complete the screw will rust as quickly as the untreated screw. The amount of carbon added to the steel to make stainless steel will also determine the rate of rusting. If the stainless steel is of poor quality it may rust, but not as much as the untreated screw.

10 In bathrooms and laundries. On the outsides of buildings. In fences and outdoor equipment.

11 In buildings and other structures near the beach.

12 Stainless steel.

13 Within buildings in a dry environment.

Worksheet 8 — After school snack

1

|Change |Physical/Chemical |Reason |

|Toasting bread |Chemical |The brown colour on the toast indicates a new |

| | |substance. |

|Spreading butter |Physical |The butter has just changed shape. |

|Spreading vegemite |Physical |The vegemite has just changed shape. |

|Cutting bread |Physical |The bread has just changed shape. |

|Boiling water |Physical |The water has been heated and could be returned to |

| | |its original temperature by cooling. |

|Dissolving chocolate powder |Physical |Dissolving is a physical change. The chocolate |

| | |powder could be recovered. |

|Cooling drink with cold milk |Physical |The drink has been cooled and could be returned to |

| | |its original temperature by heating. |

3

|Changed materials |Materials or process |

|Bread |Wheat has been ground to flour mixed with other ingredients and baked to make bread. |

| |Grinding is a physical change. Baking is a chemical change. |

Other suggestions

▪ Iron, steel and plastics to make the toaster and the electric jug.

▪ Cardboard carton or plastic bottle for the milk.

▪ Changing milk into butter.

▪ Manufacture of vegemite.

▪ Manufacture of chocolate powder.

▪ Pasteurisation and homogenisation of the milk.

Worksheet 9 — Key terms

1

[pic]

2

▪ Molecule

▪ Chemical change

▪ Soluble

▪ Bronze

▪ Rusting

▪ Dissolving

Chapter 4 — Big changes

Worksheet 1 — Thinking about a changing world.

1 Suggested changes include:

▪ Changes in the weather

▪ Changes in the seasons

▪ Leaves falling from trees

▪ New buds or flowers appearing

▪ Buildings being constructed or demolished

▪ Changes in the amount of traffic

▪ Potholes appearing in the road

▪ Friends growing taller

▪ Sun higher/lower in the sky as you walk to school

▪ Changing phases of the moon

3 Examples include: Change in the seasons, growth of plants, phases of the moon.

4 The effect on our lives of changes in the seasons or the weather. We have buildings that protect us from the weather and we can heat or cool them to make us comfortable.

We can store food for many months or years so that we are not affected by years of poor harvest.

5 Changes to buildings and roads.

Worksheet 2 — It’s light-years away

1 Each year (taking into account leap years) is 365.25 days.

700 000 divided by 365.25 equals 1916.5 years.

2 One light year is

300 000 000 × 60 × 60 × 24 × 365.25 km = 4 320 000 000 000 km

3 The size of the circle representing the Milky Way

100 000 years = 100 000 × 365.25 × 24 hours =876 600 000 hours

If the scale is one millimetre for each hour the diameter of the circle representing the Milky Way would be 876 600 000 mm. Another way of looking at it is 876.6 km which is the distance from Sydney to Melbourne.

Worksheet 3— Gravity at work?

1 a The pole of the washing line

b The rope

c The person

2 The pole and the person. Because the Sun is in the centre of the solar system and the planets revolve around it.

3 The rope. Gravity holds the planets in place but it is not a physical entity like the rope.

Worksheet 4 — Nature’s strength

1 Four months.

2 Volcanic ash from the explosion formed layers 20 to 40 m thick on islands up to 15 km away.

3 121 years

4 800 km/h

5 A massive area of land was converted into ash by the explosion. The level of the land fell by between 7000 and 3000 m. Sea water rushed into replace the land. It was this movement of water that was the tsunami.

6 A large part of an island was now a massive dust cloud being carried round the globe in a wave of moving air.

7 Vegetation would gradually return to the island. It would take many years

(100–200 years) for the forests to re-establish. If there were further eruptions the vegetation would be destroyed once again. In places inundated by salt water it would take time for the salt to be washed out of the soil by rain. Very little regrowth would occur where the ground was salt affected.

8 Information to include:

▪ Explosion was very loud 150 km away. It was heard as a faint noise over 2 700 km away.

▪ Black smoke rose 27 km into the air.

▪ A cloud of volcanic dust rose to a height of over 14 km.

▪ Cloud of dust eventually reached Europe and North America.

▪ Volcanic ash formed layers 20 to 40 m thick on islands up to 15 km away.

▪ The tsunami was 15 to 22 m high.

▪ Land that was once 100 to 4000 m above sea level was now more than 3000 m below sea level.

Worksheet 6 — Modern Fossils

1

|The materials you used |What they represent |

|Plaster of Paris |Sediments |

|Sand |Boundary between layers of sediment |

|Leaves/coins |Fossil |

|Food colouring |Colour of different sediments |

2 The fossil becomes trapped between layers of sediment.

3 Fossilisation takes a very long time – the model is created in a short time.

The fossil is changed chemically in the process (turned into rock) – there is no change to the ‘fossil’.

Sand is used to make separation of the layers easy – there may not be any equivalent to the sand in the real process.

4 Remove the object that was used to make the fossil. Spread wax on the surfaces of the rock. Pour plaster of Paris into the two moulds and smooth the surface. When the plaster of Paris is set, remove the two parts of the cast and stick them together.

Alternatively use a soft substance such as modelling clay. Place an appropriate amount into one half of the mould. Place the other half of the mould over the top and squeeze the two parts together.

5 a Sedimentation is most likely in oceans or other large bodies of water.

b These organisms are eaten or decay before sedimentation occurs.

c Many animals will not have lived in conditions that support fossilisation.

d Scavenging animals or water currents could have scattered the bones before they were covered in sediments.

Petrification is the process by which organic material is replaced with mineral from the surrounding sediments. The animal is then turned to stone. It will have the same external shape and texture but the inside is solid stone.

Carbonisation is the conversion of an organic substance into carbon or a carbon-containing residue. Fossils of this type are seen as thin layers of black in the shape of the original living thing. Plant fossils are often of this type.

Amber — organisms may become trapped and preserved in amber which is fossilised tree resin. Resin flowing from a tree is very thick and sticky. As it runs down the trunk insects, or spiders, may become trapped. These organisms can be preserved for millions of years with their soft tissue, such as muscles, still intact.

Worksheet 7 — Queensland’s past

1 Millions of years ago the area was covered in thick rainforest. Now it is a dry grassland.

2 Australia was once part of a very large landmass called Gondwana. This landmass broke up and Australia finally separated from Antarctica between 30 and 40 million years ago. It was the break up of the continent that caused the change in climate.

3 As the vegetation changed so the animals would have changed. Animals with adaptations suited to dense forest would be at a disadvantage in open grassland.

4 The environment would not be the same. Fossils form when rapid sedimentation covers the living things soon after they die so that they will be preserved. The conditions that support a dry grassland environment do not have the rainfall necessary to create the sediments.

5 Australia is moving north at a rate of about one centimetre a year.

Worksheet 8 — Key terms

1 Gravity is an attraction between two objects.

2 A supernova is the death of a star in a spectacular explosion.

3 The Earth’s surface, called the crust is made up of a number of plates that move. Sudden movements cause earthquakes. If these occur under the ocean there may be a tsunami.

4 Hot, molten material under the Earth’s crust is called magma. It collects in a magma chamber. At weak places in the crust called volcanoes it can come to the Earth’s surface. Then it is known as lava.

5 Most volcanoes have three main parts — crater, cone and a vent.

6 Weathering is the process that breaks rocks down to smaller fragments. The small fragments are then carried away by erosion.

7 Evidence of past volcanic activity includes crater lakes and volcanic plugs.

8 Lake Eacham and Lake Barrine are examples of crater lakes.

9 Sand, mud and pieces of rock carried in water and deposited on a lake or ocean floor are called sediments. The settling of the sand and mud on the ocean floor is called sedimentation. With time and pressure these sediments turn into sedimentary rocks.

10 The preserved remains or traces of organisms found in rocks are called fossils.

Chapter 5 — Safety First

Worksheet 1 — Thinking about safety first

1 Go-carting

a Protection I can see:

▪ Seat belt

▪ Roll over protection bars

▪ Safety helmet

b Why that protection is important:

▪ Seat belt prevents the driver from flying out of the vehicle if there is a crash.

▪ Roll over protection prevents the driver from being crushed if the vehicle rolls upside down.

▪ The safety helmet protects the head and brain.

2 Rollerblading

a Protection I can see:

▪ Knee, wrist and elbow protection

▪ Safety helmet

b Why that protection is important:

▪ The knee, elbow and wrist protection provides cushioning for those joints in the event of a fall.

▪ The safety helmet protects the head and brain.

3 Netball

a Protection I can see:

▪ Shoes with a good grip

b Why that protection is important:

▪ Reduces the chance of slipping and falling

Worksheet 2 — Sir Isaac Newton

1 The story goes that it was as he observed an apple falling that he wondered why it fell down instead of up or sideways His conclusion was that some force must be pulling the apple down toward the Earth.

2 The theory of gravitation.

3 The effect of gravity depends on the size of the objects and the distance between them.

4 They have helped us to learn about the Earth and other planets in the universe and understand their movements

5 All the colours of the rainbow.

6 The behaviour of light.

7 a Refracting telescope.

b Lippershay

c It has allowed us to see things not visible to the naked eye.

d

1 An object that is moving will continue to move in the same direction and at the same speed until a force acts upon it. A stationary object will remain at rest until a force acts on it.

2 The acceleration of an object increases as the unbalanced force increases, and decreases as the unbalanced force decreases.

3 For every action there is an equal and opposite reaction.

Imagine

Everything would be twice as heavy and it would be a lot more difficult to move around. Our skeletons would have to be stronger to support our weight and to prevent us from being crushed.

Worksheet 3 — What force!

2 Apply a force.

3 a The ball started to slow down.

b The ball continued to move in the same direction.

4 a Apply a force in the opposite direction to the way it is moving.

b Apply a force in the opposite direction to the way it is moving that is equal to the force moving the ball forward.

c Apply a force from the left.

d Apply a force from the right.

e Apply a force in the opposite direction to the way it is moving that is greater than the force moving the ball forward.

5 Apply a force to the ball.

6 a The ball slowed down.

b The ball may have continued to move in the same direction or it may have changed direction if it met a particularly rough area on the surface.

7 The ball slowed down more quickly. The ball may have changed direction if it met a particularly rough area on the surface.

Friction is a force that opposes the forward movement of the ball. There is more friction when an object is moving on a rough surface; when compared to a smooth surface. The force stopping the ball is greater on the rough surface therefore the ball slows down more quickly.

8 Water on a surface ‘fills in’ the small indentations that cause the roughness and therefore the friction. The surface becomes smoother and therefore more slippery.

9 The way scientists use friction it is like two forces working against each other. Friction between two people often occurs because they want different things.

10 Forces cause things to move or change shape. If you are forced to do something it may go against your ideas. You have had to change your mind and move in a direction you did not want to go.

11 Friction helped:

Walk and run; Pick up objects; Chew food; Turn pages in a book; Write with a pencil; Kick a ball; Play tennis.

Friction hindered

Cycle to school or ride on a scooter; swallow some dry food.

Worksheet 4 — Safety gear

1 To demonstrate the effect of foam padding on the fall of an object.

2 On the thicker foam the height of the bounce will be less.

3 Drop the table tennis ball from the same height each time.

Record the height of the bounce in the same way.

Measure the height of the bounce in the same way.

Repeat the activity and calculate an average.

6 The pattern should be the same with the bounce being highest with the thin foam.

7 It would be expected that the balls would bounce higher if they were dropped from a greater height.

8 Caused the ball to bounce higher.

9 The ball hits the ground with a greater force therefore the ground pushes back with a greater force.

11 The foam reduces the force with which you hit the ground.

Worksheet 5 — Inertia

1 To study the effects of inertia.

2 Information is given about placing the ‘person’ in the trolley.

Each part of the experiment is repeated so that the effects can be observed more than once.

3 The person moved backwards.

4 The person continued to move forwards.

5 The person moved forward more quickly and fell out of the trolley.

6 You are also stationary is the true statement.

7 The back of the car seat.

8 You remain stationary and the car moves forward. It is not until the back of the car seat comes in contact with your back that you start to move forward.

9 ‘at the same speed as the car’ This is the correct answer.

10 No

11 The seat belt across your body.

12 A force has caused the car to stop but the force has not impacted on you. You will continue to move forward until you meet a force pushing in the opposite direction. The seat belt is attached to the car and it will have stopped at the same time as the car. The pressure of the seat belt across your body is the force that makes you stop.

13

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Worksheet 6 — Sports medicine

1 Sports medicine deals with the care of athletes. People involved in Sports Medicine treat injuries and find ways of helping athletes to avoid problems.

2 Knee, shoulder and elbow joints

3 Cartilage in the joint reduces friction and acts as a shock absorber. Joints with arthritis do not move as easily or as smoothly. There will also be more pressure on the joints in normal activities such as walking on hard surfaces because the shock absorbing properties of the joint are lost.

4 The tendons of the elbow may have been damaged by over use.

5 a Rest and ice

b Rest from the activity that causes the injury gives the body time to heal the damage.

Ice reduces the sensitivity of the area to pain and slows the blood flow in the injured area decreasing the swelling.

c These symptoms indicate a more serious injury and should be seen by a doctor.

Worksheet 7 — Key terms

Correct words in order going down the table.

Inertia; Cartilage; Friction; Force; Gravity; Unbalanced force; Ligament; Balanced forces; Matter; Tendon; Weight; Mass.

Chapter 6 Tomorrow’s weather

Worksheet 1 — Thinking about the weather

2 Weather words — Refer to the list of key terms.

3 Ways the weather affects things that I do.

Examples include:

▪ Selection of clothes to wear

▪ Types of activities undertaken (outdoor/ indoor)

▪ Preferred food

▪ mood

Worksheet 3 — How do I feel?

1 a cold

b hot

c hot

d cold

3 Explanation: Your perception of temperature is based on previous experience. The nerves in the hand in hot water have registered the temperature. They will not react again to the same extent until the temperature changes. When that had is placed in warm water, the message sent to the brain records a drop in temperature. The interpretation is that the water is cold.

The other hand has been in cold water. When it is placed in the warm water a message is sent to the brain regarding the increase in temperature. This time the message is interpreted as the water being hot.

The previous experience of the hands determines how they feel in the warm water.

4 A — Brisbane

B — Hobart

C — Darwin

5 Explanation: The temperatures in the Gold Coast and Brisbane are almost the same. Therefore the temperature the child from Brisbane is experiencing is what they are used to. The temperatures in Hobart are usually lower than those of the Gold Coast. Therefore the child from Hobart will feel that it is hot. The temperatures in Darwin are frequently higher than those of the Gold Coast, therefore the child from Darwin would feel cool.

Worksheet 4 — Hottest and coldest

1 37°C

2

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3 Compare the January and June temperatures for each of the three places with the human body temperature.

| |January Temperature |June temperature |

|Marble Bar |Higher |Lower |

|Charlotte Pass |Lower |Lower |

|Antarctica |Lower |Lower |

Think

Possible questions.

• Our body temperature will tend to increase.

• Our body temperature will tend to decrease.

• Drink water so that we can cool ourselves by sweating. Drink cool drinks. Heating the drink inside our body removes heat from the body. Wear clothing that allows sweat to dry off. Protect ourselves from the direct rays of the sun.

• Wear clothing that covers most of our body and traps the body heat in an insulating layer. Have warm drinks.

• Yes. Even though the Sun may not produce a lot of heat in the Antarctic the UV rays that cause sunburn are still present.

• Antarctic — middle of the day when the Sun would be warmest. Marble Bar— early morning or late afternoon when the Sun is not directly overhead.

•We would have to keep warm, especially in the winter. We would also have to protect ourselves from the UV rays of the Sun.

Worksheet 5 — Rain makers

1 a Immediately — The steam from the hot water will condense on the lower

surface of the bag.

b After a longer period of time — The small drops of condensation will increase in size until they become large enough to fall back into the water.

2

|Observation |Explanation |

|Steam is rising from the hot water |Some of the hot water is evaporating to form water vapour. The|

| |water vapour is rising up inside the bottle. |

| |The water vapour is cooling and is condensing to water on the |

|Small drops of water on the underside of the plastic |cold surface of the bag. |

|bag. |As more water vapour condenses on the bag, the small droplets |

| |join together to become large droplets. |

|The water droplets on the bag are getting larger. |When the water drops become heavy enough gravity pulls them |

| |back down. This is precipitation. |

|The large water drops fall back into the water in the | |

|bottle. | |

3 Refer to Figure 6.6.

4 The sun heats the surface of water causing it to evaporate. As the water vapour rises in the atmosphere it cools and condenses back into water. The tiny water droplets float in the air as clouds. As the droplets become bigger, gravity pulls them back to Earth as rain — precipitation.

Think

• Temperature increased — The rate of evaporation would increase and more water would condense on the surface of the plastic bag. Precipitation would also occur more quickly because large water droplets would form more quickly.

• Temperature decreased — The whole process would be slowed down.

Extension

The experiment could be set up in the same way. Extra care would have to be taken if very hot water was used.

Worksheet 6 — Weather maps

1 In the high pressure the winds are anticlockwise. In the low pressure they are clockwise.

2 Any of the lines forming the high and low pressure areas.

3 The cold front is the line with the triangles.

4 The cold air is moving from west to east.

5 The air to the west will be colder. The air to the east will be warmer.

6 There are strong winds where the isobars are close together in the low pressure system.

7 There is rising air in the low pressure system.

8 There is falling air in the high pressure system.

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9 Fewer marbles were covered by the paper.

10 The mass of the marbles decreased.

11 The model was of the air being heated.

12 As air is heated the particles move further apart and the air becomes lighter. If the air in one area is lighter than the air in another area, the lighter air will rise. Therefore if air in one area is warmer than air in another area then the warmer air will rise.

Worksheet 7 — Meteorologists

1 The words will appear in this order going down the table: Weather satellites; Thermometer; Weather balloons; Anemometer; Psychrometer; Barometer.

2 They collect information about the atmosphere to try and improve our understanding of the causes of our weather and the climates throughout the world. They develop and test models for weather forecasting and climate change.

3 Improving forecasts will mean that farmers can have more confidence in forecasts of rain for crop planting. Forecasts of storms provided the opportunity to plan emergency responses. If reasons for climate change can be worked out then it may be possible to look at strategies to reduce the effect or the rate of change. Forecasts of wet or dry periods would support strategies for managing our water resources.

Worksheet 8 — Traditional weather forecasting

1 Meteorologists use information collected using instruments. Traditional cultures used observation of the clouds and animals and plant behaviour.

2 So that we can plan activities related to agriculture, building/construction, sport.

3 Knowledge of the behaviour of animals and plants used as food sources. Change of seasons.

4 One generation handing it down to the next through traditional stories.

Worksheet 9 — Greenhouses

3 The expectation is that the temperature inside the greenhouse will increase over the 30 minute period. However this will depend on factors such as the time of day and cloud cover. If thick cloud comes over during the time of the experiment the change in temperature may not be as noticeable.

4 This will depend on the time of day. In the morning you would expect the air temperature to increase. In the later afternoon it could decrease.

5 It could be expected to increase.

6 Reduce the burning of fossil fuels and of other carbon based fuels such as wood.

Worksheet 10 — Key terms

The answers will appear in this order going down the table: Blanket of air surrounding the Earth; Evaporates; Cyclone; Moving air; Turn from a gas into a liquid; The maximum temperature recorded for a period of time such as a month and then averaged over the number of records made; Gas that helps to hold the heat next to the surface of the Earth.; Climate; The minimum temperature recorded for a period of time such as a month and then averaged over the number of records made.; Any water falling from the sky; Beaufort Scale.; Condition of the atmosphere; Water vapour; Tropical cyclones; An area of cold air moving towards an area of warm air.

Chapter 7 — Use it again

Worksheet 1 — Waste audit

Examples include: Take more food than can be eaten; Buy products with a lot of packaging; Buy products that are used only once or twice.

Worksheet 2 — Biodegradable?

1 To reduce in rank or quality.

2 Life.

3 Can be broken down by the action of living things.

4

|Material |Biodegradable decision |Additional information |

|Orange peel |Biodegradable |Degrade quickly and should be completely degraded in four|

| | |weeks. |

|Apple core |Biodegradable |Degrade quickly and should be completely degraded in four|

| | |weeks. |

|Pine wood |Biodegradable |Degrades slowly but discolouration should be significant.|

|Iron nail |Non biodegradable |The iron nail should rust and break down in time but this|

| | |is a chemical reaction and not as a result of the |

| | |activity of living things. |

|Plastic bottle top |Non biodegradable |There should not be any change after four weeks. |

|Paper |Biodegradable |Degrade quickly and should be completely degraded in four|

| | |weeks. |

|Tetra pak |Biodegradable/ |Tetra pak is cardboard lined with plastic. The cardboard |

| |Non biodegradable |will degrade and may have disappeared after four weeks. |

| | |The plastic lining will not degrade. |

|Glass marble |Non biodegradable |There should not be any change after four weeks. |

|Alfoil |Non biodegradable |Alfoil may discolour. There will be chemical reactions |

| | |between the alfoil and oxygen that causes the surface to |

| | |become cloudy. Acids in the soil may also cause some |

| | |discolouration. |

|Bread |Biodegradable |Degrade quickly and should be completely degraded in four|

| | |weeks. |

|Cotton or linen fabric |Biodegradable |These will both biodegrade slowly. There may be some |

| | |change in the strength of the fibre after four weeks. |

|Polyester or nylon |Non biodegradable |There should not be any change after four weeks. |

5 Orange peel; Apple core; Pine wood; Paper; Tetra pak; Bread; Cotton or linen fabric.

6 They are either living things or are made from parts of living things.

7 Iron nail; Plastic bottle top; Tetra pak ; Glass marble; Alfoil; Polyester or nylon.

8 They have never been living.

12

|Material |Use |Suggested alternative |Biodegradable? |Additional information |

|Iron nail |Fastener in buildings and |Wooden dowel |Yes |Iron does break down (rust)|

| |furniture | | |in the soil |

|Plastic bottle top |Caps on bottles |Corks |Yes | |

|Tetra pak |Holding liquids |Glass bottles |No |Although glass is not |

| | | | |biodegradable it is |

| | | | |recyclable. |

|Glass marble |This represents all glass |No practical biodegradable| | |

| | |alternative | | |

|Alfoil |Wrapping food for cooking. |Use a container with a lid|No |The container could be used|

| | | | |over and over again. Unlike|

| | | | |alfoil that is used once |

| | | | |and disposed of. |

|Polyester or nylon |Clothing and household |Cotton, rayon and linen. |Yes | |

| |fabrics | | | |

13 They do not contribute to landfill and they can be replaced.

Worksheet 3 — Plastic — where is it from?

1 Oil started to form millions of years ago when a large sea animal died and got buried by the mud. The hydrogen and carbon that was in its body went through chemical reactions that resulted in the formation of oil.

2 The hydrogen and carbon are used in the manufacture of plastics

3 Polymer

4 many

5 Many small parts are joined together in a long chain.

6 The polymer chains lie next to each other but are not connected in any way.

7 The polymers of plastics that cannot be recycled are linked.

8 Large amounts of sediment and large numbers of organisms dying at a similar time.

9 It could be possible in some of the warmer seas where large rivers carry sediment into them.

10 It takes a very long time to form. If the oil formation process started today it would be millions of years before the oil would be usable.

Worksheet 4 — Plastics are not all the same

Household Audit

Refer to the list in section 7.3 of the student book for ideas.

Answers to the remaining questions will depend on the samples obtained and the tests students choose to undertake.

Worksheet 5— Why the packaging?

The answers to the questions on this Worksheet will depend on the samples brought in by students. Some points to consider:

Packaging is used to:

▪ Prevent breakage of the product.

▪ Attract the customer.

▪ For health reasons – tamperproof seals on pharmaceuticals, food products.

▪ Make transport of the product easier.

▪ Provide a certain amount for the consumer.

▪ Avoid perfumes or other smells affecting more than one product.

▪ Make liquids easy to carry.

Worksheet 6 — Recycling success

1 76% of the waste was recycled. 660 tonnes of waste was produced each day at the Olympic venues. Therefore 501.6 tonnes was recycled every day.

2 So that the recyclables, biodegradables and wastes for landfill could be separated easily.

3 Wastes from the cafeteria kitchen.

4 The food containers were made of biodegradable plastics.

5 The food scraps could be disposed of in the same bin.

6 In landfill

7 Timber off-cuts were mulched and used in landscaping. Bricks and concrete were processed and recycled as road base material and landscape fill.

8 It would be costly to recycle the smaller amount of wastes from individual building sites. It may be possible to separate the wastes and then dispose of them in different places at the landfill site. A central collection area could be considered for large building projects or development of new housing estates.

9 Examples include: Solar hot water systems, photovoltaic cells and building design to reduce the need for air conditioning—all of which reduced use of electricity and therefore reduced carbon emissions.

Worksheet 7 — Key terms

The answer is Queensland.

Chapter 8 — Water

Worksheet 1 — Using water

Suggested responses:

Ways I use water

Suggestions include:

▪ Drinking

▪ Bathing

▪ Flushing toilet

▪ In art class

▪ Cooking

Ways my family uses water

Suggestions include:

▪ Washing the car

▪ Watering the garden

▪ Washing clothes and dishes

▪ House cleaning

Ways society uses water

Some suggestions:

▪ Industry for cooling and in manufacturing processes

▪ Irrigation of agricultural crops

▪ Water for livestock

▪ Cleaning public places

▪ Water features in public places

Worksheet 2 — Measuring evaporation

1 To test the effect of surface area on the rate of evaporation.

2 The larger the surface area the greater the rate of evaporation.

3 Suggestions:

▪ Containers made of the same material

▪ All containers of the same depth

▪ Same amount of water added to each container

▪ All containers placed in the same conditions for the same length of time

4 The results should indicate that most water is lost form the container with the largest surface area.

7 Differences in the positions of the containers for the different groups are the most likely cause.

Worksheet 3 — Clean water?

1 Some suggestions: Soil, dead vegetation and animals, animal wastes, effluent from city sewage treatment plants; wastes from industry; storm water from cities.

2 crushed dead leaves — floated on the surface of the water

soil — made the water muddy,

rice — floated on the surface and started to swell up and fall apart

salt — did not change the way the water looked

3

|Material |Layer where it will be separated out |Reason |

|Crushed leaves |gravel |The pieces are large and will be trapped between the stones. |

|soil |Gravel and sand and paper |Soil particles are of different sizes. Some of the large ones will |

| | |be trapped in the gravel. The finest particles will be trapped in |

| | |the paper. |

|rice |Gravel and sand and paper |Most will be trapped in the gravel and sand. Some smaller pieces |

| | |could go through to the paper. |

|salt |Will not be separated |The salt is in solution and the particles are smaller than the pores|

| | |in the paper. |

4 The water cleared as the fine particles of soil clumped together.

5 Most of the soil should be trapped in the sand.

6 Salt will be in solution and will not get trapped in the filter.

7 Any bacteria in the soil or on the leaves and other dissolved substances in the soil or from the leaves will go through the filter.

8 It will look fairly clean. Possibly a little cloudy.

11 The filtered water could contain bacteria.

12 Disinfecting – treatment with oxygen or chlorine.

13 The variety of materials added to the water, the size of the pores in the various filters.

Worksheet 4 — Alternative water sources

1 ‘Water futures’ is looking at the availability of water in the future, possible alternative sources and ways of managing the water we have.

2 Suggested responses:

▪ The iceberg will melt as it enters the warmer waters of Australia.

▪ Parts might break off and they will melt more quickly.

▪ We do not have tug boats large enough to tow a massive iceberg.

▪ It would take a few months to get the iceberg to the southern coast of Australia.

▪ We do not know what effect the cold water melting from the ice will have on the marine environments off the coast of Australia.

▪ A massive iceberg would be a hazard to shipping in the Southern Ocean.

3 They would melt more quickly and there may not be any ice left by the time they get to Australia.

4 Places further north would have more problems because the sea water is warmer and it would take even longer to get the iceberg up north from Antarctica.

5 The removal of salt from water.

6 There is a permanent and plentiful supply of sea water. The supply is not dependent on rainfall.

7 Suggestions include:

▪ Reverse osmosis is part of the process of desalination and it used to be very expensive. Advances in technology have made it more energy efficient and therefore cheaper.

▪ Some of the water is returned to the ocean with a very high salt concentration. This could be a problem for marine ecosystems if the water was not returned to a place where it is very quickly mixed back into the ocean.

8 The diagram should show salt and other materials being trapped on a very fine filter. The water that has passed through the filter is safe to drink.

Challenge The answers to the challenge depend on the size of the school grounds.

Worksheet 5 — Used water

Suggested ways that water is used were provided in Worksheet 1.

Use them to estimate amounts used.

If you are using more than 140 L per day you should consider reducing your water consumption.

Water use could be reduced by:

Taking shorter showers; turning the water off while brushing teeth; only wash clothes or dishes when there is a full load in the machine; place a cover on the swimming pool; turn off any decorative water features; use mulch on the garden.

Worksheet 7 — Not down the drain!

1 Stormwater is a major source of pollution for rivers and lakes.

2 200 million litres

3 suggestions include:

• Rubbish that people throw away onto the streets especially cigarette butts and plastic bags

• Animal wastes – dog and cat droppings

• Detergents e.g. from washing cars

• Fertilisers to a small extent

• Paints

• Soil eroded from gardens

5

Advantages

▪ Less pollution would be going into waterways

▪ The wetlands could be a reserve for water birds and animals

▪ A lake could be a recreational area

Disadvantages

▪ Wetland can be a breeding ground for mosquitos and sandflies that carry disease.

▪ The wetland could be a dry unpleasant area if there is no rain in an extended dry season.

6 Refer to Figure 8.16.

7 In areas where there are very heavy downpours a raingarden may not be able to cope with the amount of water and could cause local flooding. Plants in the raingarden may not survive extended dry spells.

Worksheet 8 — Key terms

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Chapter 9 — Energy Converters

Worksheet 1 — Thinking about energy

Energy

• Energy makes changes and causes things to happen around us.

• No

• No

• No

• No

• You can see the effects of it. Things have changed shape, have moved or changed speed.

Skateboard

• From the person who is riding the skateboard.

• Suggestions include: bicycle, scooter, roller skates

Boat

• From the wind

• Suggestions include: sailboard; hang gliders; windmills

Mower

• Burning petrol

• Suggestions include: cars; buses

Arrow

• From the draw back string of the bow.

• Suggestions include: catapult (slingshot), trampoline; self-closing door.

Think

• Suggestions include: Flowing water, tidal, nuclear, heat, electrical

Flowing water — mills, turns turbines to produce electricity

Heat — hot air balloons

Electrical — electric cars; machinery, kitchen gadgets such as electric beater, food processor.

Worksheet 2 — It has potential!

1 To compare the potential energy of marbles in different situations.

6 The expectation is that the depth of the indent will increase as the height from which the marble is dropped increases.

8 Gravity pulls the marble to Earth. Lifting the marble gives the marble potential energy. As the marble is dropped the energy is released. The higher the marble is raised the more potential energy it is given and therefore the more energy there is to be released.

9 a use; energy; gave it; more; potential energy;

b potential energy; kinetic energy; more;

10

11 The depth is a measure of the amount of potential energy the marble had in the first place.

12 One suggestion: Mass of the object – the greater the mass the greater the weight (gravity acting on the mass). It takes more energy to lift an object with greater mass therefore that object will have more potential energy.

Worksheet 3 — The energy we use

1 Human power

2 They used horses and bullocks to do some of the work.

3 They used wind power to drive trading ships, power grinding mills and to pump water from lands that were once under the sea.

4 The invention of the steam engine.

5 The invention of steam engines meant that farm work could be achieved more quickly and with fewer farm labourers. In factories steam engines drove machines that carried out spinning, weaving and metal work.

6 In this context it means a complete change in something.

7 There was a complete change for the way people worked. Work previously done using human and animal power was now completed more quickly using machines.

8 Before the Industrial Revolution many people who lived in small communities often worked in their own homes or in farms nearby. As machines took over their jobs they moved to cities where large factories were established.

9 Some suggestions include: Office work, word processing, recording large amounts of information, managing information, controlling machines, carrying out dangerous tasks such as going into mines or burnt out buildings to search for information, mobile phones, i-pods

Reasons for — Suggestions include: There is a complete change in the way we live – communicate with each other, listen to music, are entertained, search for information.

Reasons against — Suggestions include: Many things we do have not changed and do not use computers.

Worksheet 4 — Today’s energy

Ways I have used energy today — Suggestions include: Running, jumping, breathing, thinking, cooking breakfast, drying hair, heating water for shower, riding in car to school, air conditioning, energy was used to make my bed, chair, clothes, school books.

Worksheet 5 — Hot water from the sun

2 Things kept the same:

▪ The amount of water being heated.

▪ The length of time the heater is in the sunshine.

▪ The time of day — preferable on the same day so that the weather conditions are the same.

▪ Position relative to the Sun.

3 The change in temperature of the water.

Results: The effectiveness of the water heater will depend on:

▪ The effectiveness of the insulation

▪ Amount of heat absorbed

▪ The surface area of the water able to absorb the heat.

Worksheet 6 — It’s changed!

1 Sun’s energy → Kinetic energy of electrons → Electrical energy

Kinetic energy of moving air → Kinetic energy of turning turbine → Electrical energy

Kinetic energy of moving water → Kinetic energy of turning turbine → Electrical energy

Chemical energy in plants → Chemical energy of methane → Burning to give heat energy → Kinetic energy of turning turbines → Electrical energy

2 a Heat as the electrons move around.

b sound and heat — the vanes of the turbines make a lot of noise. When any parts are moving against each other there will be friction which generates heat.

c Sound and heat — falling water makes a noise. There will be friction between the water particles as they move over each other. In the turbines there will be the noise of the parts moving and the heat generated by friction between the moving parts.

d Sound and heat — anything that burns produces noise. In the turbines there will be the noise of the parts moving and the heat generated by friction between the moving parts.

3 The process that has the smallest number of energy conversions in the process should be the most efficient. There are fewer opportunities for energy to be converted to wasted forms.

Worksheet 7 — Which is best?

1 Suggestions include:

▪ No electrical entertainment such as television, DVD, movies

▪ No electric light, air conditioning or heating

▪ No electric trains

▪ No electronics — computers, i-pods, mobile phones, cash registers, calculators

▪ No automatic doors

▪ No electric stoves, washing machines, dryers, electric hot water systems

▪ No electrical gadgets in the kitchen such as food processors, mixers, coffee makers, electric jugs

▪ No traffic lights or street lights

▪ No warning lights at rail crossings

2 Suggestions include:

▪ Cost to the environment – sustainability

▪ Long term availability of the saw materials

▪ Dependability of supply of the raw materials on a day to day basis

▪ Availability in all parts of the country

4 It could be best to have more than one source so that if something does happen to that source we are not left without electricity.

Worksheet 8 — The Snowy Mountains Scheme

1 Melting snow and rain in the Snowy Mountains.

2 It used to flow out to sea.

3 It is diverted through tunnels, stored in dams.

4 It is used to produce electricity and to supply irrigation water.

5 Up to ten per cent.

6 The flow has been cut by 99%.

7 When the dams were built ecosystems were flooded meaning that some plants and animals could no longer survive there. Reducing the flow to only 1% of what it was altered the environment and changed the types of living things that can survive in the river.

8 Eventually the flow of the Snowy River will be restored to 28% which is the minimum amount that scientists say the river needs to return it to good health.

9 Only two per cent of the entire scheme is visible above the ground. The other 98% is underground and construction involved a lot of tunnelling through solid granite rock.

10 Suggestions include:

▪ People are more aware now of the potential damage to ecosystems caused by dramatically changing the amount of water in a river. We are also aware that agricultural land can be damaged by too much irrigation.

▪ The additional water brings sub-surface salt to the surface killing the vegetation and making the land unusable.

▪ The monetary cost today would be prohibitive.

For these reason it would probably not be allowed to go ahead.

On the other hand:

▪ The scheme did open up large areas for farming and these areas provide a lot of the food for Australia. It would be difficult to find alternative, suitable land.

▪ Any scheme built today would look more closely at the balance between the needs of farmers and the needs of natural ecosystems. Some of the environmental problems like those caused by the Snowy River Scheme could be avoided.

Worksheet 9— Key terms — Crossword

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Chapter 10 — Under the skin

Worksheet 1 — Thinking about living things

Living things that are not animals. Suggestions include: Any plants including mosses, ferns and other non-flowering plants. Bacteria, fungi, and algae.

Parts found inside of living things. Suggestions include:

▪ Bones — make up the skeleton and support the body. (Found only in vertebrate animals.)

▪ Digestive system — helps animals get the nutrients they need out of the food they eat. Parts of the digestive system include the stomach, oesophagus, small and large intestines.

▪ Veins — carry blood from the extremes of the body back to the heart. Arteries carry the blood away from the heart. Both veins and arteries are parts of the circulatory system. The other parts are the heart that pumps the blood and the capillaries – very fine blood vessels – that join the arteries and veins.

▪ Brain, spinal cord and nerves making up the nervous system.

▪ Kidneys and bladder — parts of the excretory system.

▪ Lungs and wind pipe (trachea) — parts of the respiratory system.

Worksheet 2— Breathe like this!

1 A likeness between two or more things that is used as a basis for comparison.

2

|Part of the model |Part of the |Similarities |Differences |

| |respiratory system | | |

|Hose |trachea |Open tube |The hose is more rigid than the trachea. The trachea has to be |

| | | |held open by rings of cartilage. |

|Balloon |lung |Both are sacs that can be |The balloon is a single space. The lungs are made up of millions |

| | |filled with air. |of microscopic sacs — alveoli. |

|Bottle |ribcage |Forms a outer layer of the|The glass bottle is rigid. In the rib cage the ribs have muscles |

| | |respiratory system |between them. This enables the ribcage to move up and out as we |

| | | |breathe in. The ribcage also moves down and in as we breathe out. |

|Cling wrap |diaphragm |Both are a thin layer of |The diaphragm is able to move by itself. |

| | |elastic tissue. | |

3 So that there is only one way that air can enter or leave the system. If the joints were not air tight the balloon (lung) would not inflate.

4 The same number of particles evenly spaced out in each box.

5 The air particles would move to fill the space inside the larger box. The air pressure would be reduced.

6 When the air pressure inside the box is less than the air pressure outside the box, air would move into the box through the hole.

7 The air pressure would increase.

8 When the air pressure inside the box is greater than the air pressure outside the box, air would move out of the box through the hole.

9 Moving the ribs up and out, and flattening the diaphragm, increases the space inside our chests. The air in the lungs spreads out and the air pressure is reduced becoming less than the air pressure outside. Air therefore moves into the chest through the windpipe.

When the ribs move in and down and the diaphragm arches up the space inside out chest is reduced. The air particles move closer together and the pressure inside the chest becomes greater than the pressure outside. Air therefore moves from inside the chest to the outside through the windpipe.

Worksheet 3— Cells and structure

1 To compare plant and animals cells.

2 a Box represents the cell wall.

b Balloon represents the cell membrane.

c Water represents the cytoplasm.

3 It took up the shape of the box.

4 Rigid

5 More rigid. The water filled balloon would be exerting more pressure on the sides of the box.

6 The balloons would become more floppy and would move away from the sides of the box.

8 The balloons slid over each other or pushed the others out of shape. They form a shapeless mass.

10 The balloons could be attached to a framework in the shape of the required animal.

11 Their skeleton provides them with their shape. The cells are attached to each other and to the skeleton.

12 Advantages of having a cell wall.

Suggestions include:

▪ Cell walls provide as firm layer on the outside. This gives some protection form external impacts.

▪ The cell wall separates the cells to some extent. Damage to one cell may not extend to easily to other cells.

▪ If water starts to move into a cell the cell wall will stop the membrane from expanding so far that it bursts.

Disadvantages of having a cell wall.

Suggestions include:

▪ The rigid outer covering makes it more difficult for cells to change their size. Only a limited amount of water would be able to enter a cell at any time

▪ The softer cell mass of the animal body absorbs impact to some extent. The more rigid cell of the plant could be damaged by the same impact.

▪ The plant cells are not flexible.

Advantages of not having a cell wall

Suggestions include:

▪ The mass of cells is more flexible and can mould to different shapes and can stretch.

▪ If water starts to move into the cells they can keep expanding until they burst.

Disadvantages of not having a cell wall.

Suggestions include:

▪ There is not protection for individual cells from external impacts.

▪ A skeleton of some kind is required if the mass of cells is to have some shape that can be maintained on land. (The shape of jellyfish is maintained as the body floats in the water.)

Worksheet 4— Stem cells

1 Scientists were experimenting with bone marrow to use in the treatment of leukaemia.

2 Stem cells are the cells that allow us to regenerate and repair our tissues.

3 They were first found in 1998. (Calculate how long ago it was.)

4 Adult stem cells are only able to make certain types of cells. For example blood stem cells normally only give rise to blood cells. Embryonic stem cells have the potential to make all the types of cells found in the human body.

5 The embryo is destroyed when the stem cells are gathered and this conflicts with the religious and moral views of some people.

6 Scientists think that stem cells have the potential to treat and hopefully cure diseases such as cancer, diabetes, heart disease, and spinal-cord injuries where cells have been damaged. Through stem cell research scientists may discover new drugs and test them leading to a better understanding of the human body and how it develops.

There are ethical issues surrounding embryonic stem cell research. For many people the biggest problem is that the embryo is destroyed when the stem cells are gathered and this conflicts with the religious and moral views they hold. For supporters of stem cell research the potential for treatments and possibly cures for illnesses that at present have no cure is very important.

7 He suffered spinal cord damage in a horse riding accident. He became a quadriplegic. He hoped that stem cell therapy would enable him to walk again.

Worksheet 5 — Sorting for a reason

1 Suggestions include:

|Names of the groups |Reason for sorting in that way |

|Circles |The groups represent different shapes. |

|Triangles | |

|Crosses | |

|Spots |The three groups have different patterns. |

|Stripes | |

|Plain | |

|Large |The three groups represent shapes of different sizes. |

|Medium | |

|Small | |

|Straight |In some shapes (the crosses and the triangles) all the sides are |

|Curved |straight. The circles have curved lines at their boundary. |

2 The first one (crosses, circles and triangles) it seems more useful to group together the shapes that are the same. The pattern and size seem less significant.

3 Suggestions include:

|Names of the groups |Reason for sorting in that way |

|African |Separates the animals in terms of where they are found. |

|Australian | |

|4 legs |It provides an indication of how the animals might move. |

|2 legs | |

|0 legs | |

|Fur |Provides an indication of the body covering. |

|Feathers | |

|Scales | |

|Bird |The body covering is one of the characteristics separating the groups but |

|Mammal |there are others such as: |

|Reptile |Birds — wings, scales on legs, lay hard shelled eggs |

| |Mammal — feed young on milk produced by mother, most give birth to live young |

| |Reptile — most lay soft shelled eggs |

4 The separation into birds, mammals and reptiles because it provides most information about the animals and links them to other similar animals not included on the list.

Worksheet 6 — Kingdom Monera

1 All the bacteria are in the kingdom Monera.

2 Bacteria that cause disease.

3 No. We have bacteria living inside us and on our skin that help us fight off disease. They are essential to out good health.

Vitamin K is necessary if our blood is going to clot normally. About half the vitamin K we need is made by bacteria in our gut.

4 Cheese and yoghurt.

5 Suggestions include:

▪ Help us fight disease.

▪ Make vitamin K.

▪ Used in the manufacture of foods such as cheese and yoghurt.

▪ Help farmers maintain healthy soil by breaking down dead plant and animal tissues returning nutrients to the soil.

▪ Breakdown wastes in sewage treatment plants, turning them into forms that are harmless and useful.

6 Suggestions include:

• Spoil food and have the potential to cause food poisoning.

• Cause human diseases such as cholera, meningitis, tetanus and Legionnaires disease.

• Cause disease in plants and animals.

• Cause corrosion in steel and concrete pipes through the production of acid.

Worksheet 8— Key terms

1 cell

2 tissue system

3 lung lung alveoli

4 specialised

5 nucleus cytoplasm plasma membrane cell wall chloroplasts

6 vertebrates invertebrates

7 kingdoms Monera Protists Fungi Plants Animals

8 Monera pathogenic

9 species smaller species

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A

U

A

R

R

Natural material that can be produced again and again.

E

L

Iron ore

E

E

C

Q

Composting

D

N

L

A

U

biodegradable

Bauxite

N

S

R

Q

Decompose

Anything that is not wanted.

Building block of plastics.

Resources that once they have been used cannot be replaced.

An area of land where solid waste is dumped.

Ore used to make iron and steel.

When parts of plants are broken down by bacteria and fungi they ...............

Way of recycling biodegradable wastes.

Can be broken down by bacteria and fungi in the soil.

Ore from which aluminium is obtained.

Renewable resource

Waste

polymer

Non renewable resources

Landfill

The thump as the marble hit the ground

The marble falling

Kinetic energy

Kinetic energy

Potential

energy

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