8th Grade Integrated Science



Name: _______________________________________________________________ Period: _____________

Chemistry Practice Exam

Work with a group to finish the practice exam. Then correct your test to see what you still need to study!

1. How many protons does an atom of Sulfur have?

2. How many electrons are there in a neutral atom of Arsenic?

3. How many valence electrons does an atom of Flourine have?

4. What makes an oxygen atom different from a carbon atom?

a. the number of neutrons b. the number of electrons

c. the number of valence electrons d. the number of protons

5. Why is the periodic table grouped into columns?

a. Elements in the same column have the same number of electrons

b. Elements in the same column have the same number of protons

c. Elements in the same column have the same number of valence electrons

d. Elements in the same column have the same number of neutrons

6. How many atoms of Oxygen are in Nitroglycerin (chemical formula C3H5N3O9)

7. Why do atoms make chemical bonds?

a. so they can have a full outer shell of electrons

b. because they get bored and want something to do

c. because they want to get rid of their extra electrons

d. because the strong force pulls them together

Label the parts of this model of the atom.

8.______Neutron

9.______Proton

10.______Electron

11. What is the atomic number of this element?

a. 4 b. 2 c. 6 d. 1

12. What is the mass number?

a. 3 b. 2 c. 5 d. 1

13. How many atoms of Hydrogen are in rubbing alcohol (C3H8O)?

14. Which of the following drawings is correct for the element Flourine (atomic number = 9, mass number = 19)?

a. b. c. d.

15. How many molecules of water are produced in this reaction?

2C3H8O + 9O2 ( 8H2O + 6CO2

16. How many neutrons does an atom of Phosphorus (P) have?




17. Diamonds are sometimes used as the tips of drill bits. Which physical property of a diamond MOST likely makes it a good cutting tool?

A) its electrical properties

B)  its thermal properties 


C)  its hardness 


D)  its density 


18. A teacher breaks a bar of pure copper into two different sized pieces. Which is the MOST likely difference between the two pieces?

A) mass
B) texture
C) boiling point D) melting point

19. A teacher asks her students to examine titles of four scientific articles. Which titled article is specifically about a chemical change?

A) How Baking Soda Reacts With Vinegar

B) How Rust Can Be Scraped off of Metal

C) How Elements Can Change Phase When Heated

20. The table describes three substances.

[pic]

What process will BEST separate these components?

A) using a magnet, filtration, and evaporation

B)  using a magnet, a blender, and filtration 


C)  using a blender, filtration, and evaporation 


D)  using a blender, evaporation, and a magnet 


21. A potter molded wet clay into the shape of a bowl and let it dry.

[pic]

The potter knows that the clay went through a physical change when it became a bowl because the bowl

A) is a different color than the wet clay.

B)  is the same substance as the wet clay. 


C)  has a different texture than the wet clay. 


D)  holds the same amount of water as the wet clay.

22. An artist carves a statue by chipping off pieces from a marble slab.

[pic]

Which of these is the BEST reason to describe the carving as a physical change?

A) The statue is the same substance as the slab.

B)  The statue is made from a natural material. 


C)  The artist uses a chisel to make the statue. 


D)  The artist will work many hours to make the statue. 


23. Which event is an example of a chemical change?

A) Fog rising off a river

B)  wood burning in a fireplace 


C)  Ice cream melting in the sunshine

D)  grinding peppercorn into pepper flakes

24. When iron combines with oxygen in a moist environment, rust forms because of a

A) chemical reaction

B)  physical reaction. 


C)  change in density 


D)  change in temperature

25. Emily made a chart that included physical changes and chemical changes. Which change should be categorized as a chemical change?

A) iron becomes rusty

B)  a gold bar is melted 


C)  lake water evaporates

D)  a granite rock is polished

26. Matter can undergo different changes. Which BEST demonstrates a chemical change?

A) salt dissolving

B)  wood burning 


C)  water boiling

D)  ice melting 


27. Students performed an investigation on how aluminum cans taken to a recycle center were able to be reused. They found out an aluminum can undergoes which type of change?

A) a physical change because the can is heated

B)  a chemical change because new metal is formed 


C)  a physical change because the material remains the same

D)  a chemical change because the can is changed into a new can


28. When frozen carbon dioxide is heated, it changes directly into a gas. Which statement BEST indicates that a physical change has taken place?

A) heat cause an increase in gas production

B)  Heat caused a new substance to form. 


C)  heat caused a decrease in energy

D)  heat caused a change in state.

29. A student mixed some yellow sulfur powder with some iron filings. She was able to take the iron out of the sulfur by using a magnet. She then remixed the iron and sulfur in a test tube and heated it. After it cooled, she removed the substance from the test tube but could not separate the iron from the sulfur using the magnet. Which type of change occurred in the material when it was heated?

A) a physical reaction because the iron reacted with the sulfur

B)  a chemical change because a new substance was formed

C)  a physical change because the compound was formed

D)  a chemical change because a magnet had to be used

30. A student kept a notebook during an investigation. Which recorded observation was MOST likely a physical change?

A) the solution was heated for two minutes before it boiled

B)  A solid formed when two liquids were mixed together.

C)  two solutions were mixed and the resulting solution was hot

D)  the color of two mixed solutions changed from clear to white.

31. Chemical change can be identified by specific observations. Which would MOST likely indicate a chemical change?

A) Solid carbon dioxide changes directly into carbon dioxide gas.

B)  Rock is slowly worn away by the action of wind and sand. 


C)  A mineral is crushed into fine dust and mixed with water. 


D)  A light green powder forms on the outside of a penny. 


32. Missy and Ethan discussed examples of the types of changes in matter. In which example is a chemical change taking place?

A)  A piece of metal is cut in half. 


B)  An ice cube melts on a counter. 


C)  A camper roasts marshmallows over a burning fire. 


D)  A baker mixes together flour and sugar to make dough. 


33. Which is evidence of a chemical reaction?

A) the light produced by magnesium when burned

B)  the evaporation of water from a solution 


C)  the fizzing of a soft drink 


D)  the heat from a light bulb 


34. Magnesium strips are long, thin strips that are gray and shiny. Which action will lead to a chemical change of magnesium strips?

A) putting them in the freezer

B)  burning them with a candle 


C)  cutting them into small pieces 


D)  mixing them with pieces of copper 


35. Which of these is an example of a chemical reaction?

A) storing milk by putting it into the freezer

B)  milk turning sour when left in a warm place 


C)  mixing milk into a glass with chocolate powder 


D)  allowing milk to evaporate, leaving behind powdered milk 


36. Which of the following increases the rate at which a solid solute will dissolve in a beaker of water?

A) placing the beaker in a bucket of ice

B)  adding the solute slowly into the beaker 


C)  crushing the solid before placing it into the beaker 


D)  shaking the beaker before placing the solid in 
. 


Use this graph to answer the following questions. Water is placed over a burner and it boils. The graph shows the temperature at each 2-minute interval. The experiment ended at 20 minutes.

[pic]

48. If the water were left to boil for 10 minutes more, how hot would it get?

a. 32°C

b. 100°C

c. 160°C

d. 212°C

49. At which point on the graph do the molecules have the most energy?

a. A

b. B

c. C

d. D

50. How hot was the water at 6 minutes?

a. 20°C

b. 40°C

c. 60°C

d. 80°C

51. Toniqua and Juan decide to do an experiment. One of them will put a drop of food coloring in hot water; the other will put a drop of food coloring in cold water. Based on your knowledge of energy and the motion of particles in a substance, predict the results of their experiment.

a. The coloring will move through both containers of water at the same speed because water always has the same energy

b. The coloring will move through the cold water faster because cold water has more energy

c. The coloring will move through the hot water faster because hot water has more energy

d. The coloring will float on top of the water until your put energy into it by stirring it

52. Which of the following is an example of a chemical change?

a. Bending a pop can

b. Evaporation of milk

c. Melting wax

d. Burning paper

53. In a laboratory experiment, you mix two colorless liquids together. After a few minutes you notice the liquid has turned purple. What can you infer has happened?

a. A physical change has taken place, and a mixture has formed

b. A chemical change has taken place, and a mixture has formed

c. A physical change has taken place, and a new substance has formed

d. A chemical change has taken place, and a new substance has formed

54. As warm air rises, it cools, condenses and freezes in the upper atmosphere. What happens as it falls back to Earth as rain?

a. It undergoes no chemical or physical change

b. It undergoes a physical change from solid to liquid

c. It undergoes a physical change from solid to gas

d. It undergoes a chemical change from solid to gas

e. It undergoes a chemical change from a solid to liquid

55. A student uses clay to model the conservation of mass. First, she weighs a block of clay on a balance. Then she molds the clay into a different shape, without adding or removing clay. Finally, she weighs it again. How will her results model this law?

a. They will show that the shape has changed, but the weight is the same.

b. They will show that the shape has changed and the weight has also.

c. They will show the changing shape has changed the weight of the clay.

d. They will show that the larger the shape, the greater the weight.

48. Study the list of potential chemical and physical changes below. Then answer the question that follows.

A. Jim uses baking soda and vinegar to make bubbles to erupt a model volcano.

B. Fred left a sack of steel nails out on the porch where they got wet and rusted.

C. Jack scraped flint across steel to light his cigarette lighter.

D. The door panel of Jan's old truck has the paint scraped off and is rusted.

E. Jane strikes a sulfur match rapidly across a hard surface to light it.

F. Jill uses baking powder in her biscuits to cause bubbles to form in the cooking dough. What conditions would indicate rusting might take place in some of these chemical reactions?

a. wet metal in air

b. heat generated

c. energy is absorbed

d. bubbles in air

49. Which of the following is true of chemical properties?

a. They describe the phase the substance is in

b. They describe characteristics of a substance such as size, color, and shape

c. They explain how the substance reacts with other substances

d. They describe what chemical changes the substance is currently going through

50. Heat is energy that causes particles of matter to move faster and farther apart. As particles move faster, they leave one phase and enter another. According to the diagram, at which point is a phase change taking place?

a. A

b. B

c. C

d. E

51. The Law of Conservation of Mass states that matter is not gained or lost in a chemical reaction. Which of the following correctly restates this law? In a chemical reaction…

a. The amount of mass of the reactants will equal the mass of the products.

b. The amount of mass is equal to the sum of the reactants and products.

c. Matter is gained and lost in depending on how much energy is added.

d. Matter is gained and lost but energy is conserved.

52. A chemical change occurs when an egg cooks. What effect does the chemical change have on the physical properties of the egg?

a. The egg is unchanged

b. The egg has new physical properties.

c. The egg cannot be measured

d. The egg has doubled in size.

53. A bag containing several chemicals is used for sports injuries. When chemicals are combined, the bag becomes cold. What is this evidence of?

a. A physical change

b. A chemical change

c. A nuclear change

d. An atomic change

54. Students heated a strip of magnesium in a flame. They held it with tongs and timed the reaction. Which question did the students test?

a. How long does it take for magnesium to get hot enough to burn?

b. Does magnesium burn?

c. How much magnesium will burn once it starts?

d. What does magnesium turn into when it burns?

-----------------------

+

+

a

b

c

= 15

N = 16

= 15

N = 16

= 15

N = 16

= 15

N = 16

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download