PDF Grade 10 Physical Sciences Lesson Plans

Grade 10 Physical Sciences Lesson Plans

GRADE

10

SUBJECT Physical Sciences

WEEK

14

TOPIC

Physical and Chemical change (chemical change) - Time: 60 minutes

Lesson

1&2

LESSON SUMMARY FOR: DATE STARTED:

DATE COMPLETED:

LESSON OBJECTIVES

At the end of this lesson learners should be able to: Describe what happens to matter when it undergoes a chemical change. List examples of chemical changes that matter undergoes. The following results will be the outcome of this lesson: To re-enforce the concepts of physical and chemical change. The learners being able to describe and explain the chemical changes that elements and compounds undergo.

1. TEACHING METHOD/S USED IN THIS LESSON: Question and Answer; Narrative

TEACHING and LEARNING ACTIVITIES

2. LESSON DEVELOPMENT 2.1 Introduction Introduce the lesson with an exciting demonstration/ experiment OR explain an example where the lesson is applied to life in general. e.g. Half fill a test tube with HYDROGEN PEROXIDE liquid, wait a few minutes and note what happens. Add a pinch of manganese dioxide and note what happens. Learners observe the experiment/ record their results and observations/ listen and follow demonstration. [20 min.]

PRE-KNOWLEDGE A basic understanding of : Atoms; molecules ; compounds and elements Matter and the different phases in which it is found in. Chemical changes and how to explain what happens in a chemical change.

EDUCATOR tests pre-knowledge by using the question and answer method as indicated in the baseline assessment. BASELINE ASSESSMENT: QUESTIONS/ ACTIVITY [10 min.] What is matter? What are the components of matter? What are the different phases of matter? What are atoms? Give examples.

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Grade 10 Physical Sciences Lesson Plans

What are molecules? Give examples. What is a physical change and list examples of physical changes. What is a chemical change and give examples of chemical changes.

2.2 Main Body (Lesson presentation) Educator starts lesson off with an exciting demonstration as mentioned in the introduction and explains the relevant concepts in terms of a chemical change. [20 min.] Matter is all around us and it undergoes changes all the time, these changes can be classified as PHYSICAL CHANGES OR CHEMICAL CHANGES. The CONCEPTS of PHYSICAL CHANGE and CHEMICAL CHANGE is shown in the table below, educator engages learners in a discussion of the different aspects of physical and

chemical change as mentioned in the table to re-enforce the concepts.

physical changes

common signs that a chemical change has occurred are:

1. Production of gas bubbles 2. Change in the way something smells 3. A release of energy such as a flash or a sound (like a firecracker) 4. A precipitate forms (two liquids mixed together form a solid and a liquid)

Examples of physical changes

? A grape when stepped on (changes shape) Blowing up a balloon (changes size and shape) ? Liquid water turning to ice (changes state of matter) ? Liquid water turning to steam (changes state of matter) ? Mixing salt and sugar (changes the appearance, but you can still separate the mixture) ? Mixing water and salt (changes the appearance, but you can still separate the mixture)

chemical changes

common signs that a physical change has occurred are:

1. change in the size 2. change in shape, 3. change in colour, or 4. Change in state/ phase of matter of a substance. 5. No new substance is produced.

Examples of chemical changes

Metal rusting (new substance formed) ? Stomach digesting food (break down of food to new substances) ? Plant carrying out photosynthesis (putting water and carbon dioxide together to make sugar) ? Mixing baking soda and vinegar (makes a neutral liquid and a gas)

Educator discusses the results of the experiment with the learners. The liquid hydrogen peroxide decomposes (breaks up) to form oxygen gas and liquid water (The atomic model the using ball and stick as well as space filling diagrams to show

the reactants and products in this reaction). The MANGANESE DIOXIDE is a catalyst and speeds up the reaction. A CATALYST is a chemical substance that changes the speed of a reaction without getting used up in the

process, at the end of the reaction the catalyst can be recovered. Eg. ENZYMES in our body help to speed up the digestive process.

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Grade 10 Physical Sciences Lesson Plans

Hydrogen Peroxide 2 hydrogens: 2 oxygens

Water 2 hydrogens : 1 oxygen

Oxygen gas 2 oxygens

Educator engages learners in a question and answer session with regards the observations they have made. What do the products look like? How are they different from the original substances in terms of colour; phase; feel; smell etc.? Do the products have any of the properties of the original reactant, eg? Hydrogen peroxide is highly corrosive (burns your skin burning sensation), can be used as a bleaching agent (removes colour/ cleaning of metals)

3. Conclusion and Chalkboard summary Activity to Re-enforce lesson (Educator explains main concepts of the lesson and summarises points on chalkboard. (CHALKBOARD SUMMARY). [10 min.] During a Chemical change the particles themselves are changed in some way. There are greater energy changes that take place in a chemical change as compared to a

physical change. The changes in energy are because energy is needed to break up bonds and then energy is given off when bonds are formed in the new products. It is very difficult to reverse a chemical change as can be seen from the fried egg that forms when the liquid egg is heated. In most chemical changes that take place the total mass remains of the reactants and products remain the same but the number of atoms and molecules change as shown below:

Hydrogen Peroxide 2 hydrogens: 2 oxygens

Water 2 hydrogens : 1 oxygen

Oxygen gas 2 oxygens

HOMEWORK QUESTIONS/ ACTIVITY (educator must give learners a few questions to answer at home by either writing them on the chalkboard or giving an exercise from the prescribed textbook) [10 min]

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Grade 10 Physical Sciences Lesson Plans

i.e. 1. For each of the following say whether a CHEMICAL CHANGE or a PHYSICAL CHANGE occurs: 1.1 Melting candle wax. 1.2 Mixing sodium chloride and silver nitrate to form silver chloride and sodium nitrate. 1.3 Dissolving salt in water. 1.4 Melting a piece of plastic. 1.5 Burning a piece of paper. 2. Explain your answer for each of the changes that took place in the situations from 1.1 To 1.5.

RESOURCES USED: Relevant apparatus (models/ atomic kits) and chemicals for practical demonstration; worksheet/ transparency for baseline assessment; relevant textbook/ notes eg (CAPS document pg. 35-37; chapter 12 from textbook PHYSICAL SCIENCES 10 pg. 109-113 (platinum series- Grayson; Harris; Mckenzie and Schreuder); grade 10 physical science version 1 caps pg. 192-196(Siyavula and volunteers).

Reflection/Notes:

Name of Teacher: Sign: Date:

HOD: Sign: Date:

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? Gauteng Department of Education (ver.1)

Grade 10 Physical Sciences Lesson Plans

GRADE

10

SUBJECT

Physical Sciences

WEEK

15

TOPIC

Physical and Chemical change (conservation of matter) ? Time: 60 minutes

Lesson

1

LESSON SUMMARY FOR: DATE STARTED:

DATE COMPLETED:

LESSON OBJECTIVES

At the end of this lesson learners should be able to: Illustrate the conservation of atoms and the non-conservation of molecules using atomic model diagrams (ball and stick and space filling) The following results will be the outcome of this lesson: To re-enforce the concepts of physical and chemical change. The learners being able to use atomic models and diagrams to describe and explain the chemical changes that elements and compounds

undergo.

1. TEACHING METHOD/S USED IN THIS LESSON: Question and Answer; Narrative

TEACHING and LEARNING ACTIVITIES

2. LESSON DEVELOPMENT

2.1 Introduction: Educator introduces the lesson with an exciting demonstration/ experiment OR explains an example where the lesson is applied to life in general. eg: Use the atomic model kit if available or use toothpicks and jelly tots to build the atomic/ molecular models for the reaction for the formation of the water molecule from the hydrogen molecule and the oxygen molecule and also build models for the decomposition of hydrogen peroxide reaction. Use these models to show the conservation of atoms and the non-conservation of molecules in a physical change. Learners observe the experiment/ record their results and observations/ listen and follow demonstration. [20 min.]

PRE-KNOWLEDGE A basic understanding of : Atoms; molecules ; compounds and elements Chemical changes and how to explain what happens in a chemical change.

EDUCATOR tests pre-knowledge by using the question and answer method as indicated in the baseline assessment. BASELINE ASSESSMENT: QUESTIONS/ ACTIVITY [10 min.]

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Grade 10 Physical Sciences Lesson Plans

What is matter? What are the components of matter? What are the different phases of matter? What are atoms? Give examples. What are molecules? Give examples. What is a physical change and list examples of physical changes. What is a chemical change and give examples of chemical changes.

2.2 Main Body (Lesson presentation) Educator explains the LAW of CONSERVATION of MATTER using the different models as well as diagrams and equations. [20 min.] In a chemical reaction the TOTAL NUMBER of ATOMS remains CONSTANT BUT the NUMBER of MOLECULES may CHANGE as seen below in the reaction equations for the formation of water from hydrogen gas and oxygen gas and the decomposition of hydrogen peroxide.

2H2

+

O2

2H2O

2 Hydrogen Peroxide molecules = 4 hydrogen atoms + 4 oxygen atoms = 8 atoms

2 Water molecules = 4 hydrogen atoms + 2 oxygen atom = 6 atoms

1 Oxygen molecule = 2 oxygen atoms

The LAW of CONSERVATION of MATTER states that when elements and compounds bond to form new products in a chemical reaction the number of atoms of each type of element remains the same before and after the reaction.

ANOTHER 2 EXAMPLES SHOWN BELOW to indicate that ATOMS ARE CONSERVED in a CHEMICAL REACTION.

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Grade 10 Physical Sciences Lesson Plans

3 molecules of hydrogen gas 6 atoms of hydrogen

3H2

+

N2

1 molecule of nitrogen gas

2 atoms of nitrogen

2NH3 2 molecules of ammonia 6 atoms of hydrogen and 2 atoms of nitrogen

2SO2

+

2 molecules of sulphur dioxide gas

2 atoms of sulphur and

4 atoms of oxygen

O2 1 molecule of oxygen gas 2 atoms of oxygen

2SO3

2 molecules of ammonia 2 atoms of sulphur and 6 atoms of oxygen

CLOSED SYSTEM is when no outside factors (heat, other substances etc.) are added to the reaction to change the conditions to affect the reaction. Eg. Container must be closed when gases are involved.

3. Conclusion and Chalkboard summary Activity to Re-enforce lesson (Educator explains main concepts of the lesson and summarises points on chalkboard. (CHALKBOARD SUMMARY). [10 min.] During a Chemical change the particles themselves are changed in some ways. There are greater energy changes that take place in a chemical change as compared to a

physical change. The changes in energy are because energy is needed to break up bonds and then energy is given off when bonds are formed in the new products. It is very difficult to reverse a chemical change as can be seen from the fried egg that forms when the liquid egg is heated. The total mass remains constant but the number of atoms and molecules change in most chemical reactions as shown above in the ball and stick and space filling models in the reaction with hydrogen peroxide.

HOMEWORK QUESTIONS/ ACTIVITY (educator must give learners a few questions to answer at home by either writing them on the chalkboard or giving an exercise from the prescribed textbook) [20 min] i.e. 1. Copy the following diagrams in your books and complete the parts of the atoms and molecules that are missing.

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Grade 10 Physical Sciences Lesson Plans

HYDROGEN GAS + OXYGEN GAS

WATER

2. Draw the ball and stick models for the following chemical equations: Balance the following equations. All the reactants and products are shown.

2.1 Magnesium is burned in oxygen to give magnesium oxide:

2.2 Carbon and chlorine gas react to form carbon tetrachloride:

2.3 Potassium oxide is formed by burning potassium in oxygen: K + O2

K2O

2.4 Hydrogen reacts with chlorine gas to form hydrogen chloride: 3. Now balance the number of atoms and molecules on the product side and the reactants side of the equation. Draw the ball and stick models for the above balanced chemical equations: RESOURCES USED: Relevant apparatus (models/ atomic kits) and chemicals for practical demonstration; worksheet/ transparency for baseline assessment; relevant textbook/ notes eg (CAPS document pg. 35-37; chapter 12 from textbook PHYSICAL SCIENCES 10 pg. 112-116 (platinum series- Grayson; Harris; Mckenzie and Schreuder); grade 10 physical science version 1 caps pg. 197-201(Siyavula and volunteers).

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