Chemical and Physical Changes

Question 1

a characteristic of a substance that can be observed directly or measured with a tool without changing the identity of the substance

Answer 1

Physical Property

Question 2

a change in a substance that does not change the chemical makeup of the substance

Answer 2

Physical Change

Question 3

a characteristic of a substance that cannot be observed without changing the identity of the substance

Answer 3

Chemical Property

Question 4

a change that results in the formation of a new substance or substances

Answer 4

Chemical Change

Question 5

a solid that forms during a chemical reaction that takes place in a solution

Answer 5

Precipitate

Question 6

the forces that hold atoms together in molecules

Answer 6

Chemical Bond

Question 7

process by which elements and compounds combine to form new substances

Answer 7

Chemical Reaction

Question 8

Which indicates a chemical reaction is occurring
A. A substance melting
B. A substance evaporating
C. Bubbles forming when 2 substances are mixed
D. Temperature remaining the same when 2 substances are mixed

Answer 8

C. Bubbles forming when 2 substances are mixed

Question 9

Which is the BEST evidence of a chemical change occurring when bread is baked?
A. The bread is warm and soft
B. Steam rises from the bread after it is baked
C. The dough rises during baking, and its texture changes
D. The bread appears exactly the same before and after baking

Answer 9

C. The dough rises during baking, and its texture changes

Question 10

Which of these is NOT an example of a physical change of state?
A. Boiling
B. Stirring
C. Freezing
D. Evaporating

Answer 10

B. Stirring

Question 11

Which is indicated if a gas forms when 2 or more substances are mixed?
A. Physical change
B. Chemical change
C. Physical property
D. Chemical property

Answer 11

B. Chemical change

Question 12

Which BEST describes the solid that forms when 2 liquids combine in a chemical reaction?
A. Gas
B. Energy
C. Precipitate

Answer 12

C. Precipitate

Question 13

Which task in the kitchen is a physical change?
A. Frying an egg
B. Baking a cake
C. Melting butter
D. Toasting bread

Answer 13

C. Melting butter

Question 14

An ice cube is put into a heated pan. What will MOST LIKELY happen to the molecules in the ice as it is heated?
A. The molecules will begin to move slower
B. The molecules will begin to move faster
C. The molecules will begin to increase in density
D. The molecules will begin to condense in the air

Answer 14

B. The molecules will begin to move faster

Question 15

Which is the BEST description for iron rusting quickly when exposed to water and salt?
A. A change of state
B. A chemical reaction
C. A physical reaction

Answer 15

B. A chemical reaction

Question 16

Liquids placed in a beaker will settle in specific layers. Which physical property of matter does this illustrate?
A. Density
B. Polarity
C. Solubility
D. Malleability

Answer 16

A. Density

Question 17

Which is a physical change?
A. A piece of wood burning
B. A copper roof changing color
C. Rust forming on an iron fence
D. A sheet of paper shredding

Answer 17

D. A sheet of paper shredding

Question 18

Which is an example of a chemical reaction?
A. Vinegar added to baking soda forms a gas
B. Water evaporates into the air
C. Sugar dissolves in water
D. Corn kernels are crushed to form cornmeal

Answer 18

A. Vinegar added to baking soda forms a gas

Question 19

Which of these could be a physical change?
A. Wood is burned in a fireplace
B. Cake batter is baked in an oven
C. A blue liquid and yellow liquid mix and make a green liquid
D. Baking soda is mixed with vinegar to make CO2

Answer 19

C. A blue liquid and yellow liquid mix and make a green liquid

Question 20

Jay mixed 2 clear liquids and observes that they turn a cloudy white. Which MOST LIKELY happened?
A. Heat was given off
B. Rust was produced
C. The mass increased
D. A precipitate formed

Answer 20

D. A precipitate formed

Question 21

Which is the BEST evidence that a chemical change has occurred?
A. Change of state
B. Release of energy
C. Temperature change
D. Formation of a new substance

Answer 21

D. Formation of a new substance

Question 22

What part of digestion is mainly a chemical change?
A. Teeth break food into small pieces
B. Throat muscles push food toward the stomach
C. Stomach acids dissolve food into nutrients
D. Intestinal cells transport nutrients into the blood

Answer 22

C. Stomach acids dissolve food into nutrients

Question 24

Which chemical change is MOST LIKELY to involve bubbling or an odor?
A. Color change
B. Gas production
C. Precipitate formation
D. Temperature decrease

Answer 24

B. Gas production

Question 25

Which MOST LIKELY indicates a precipitate formed during a reaction?
A. The liquids changing colors
B. A solid appearing in the liquid
C. Gas bubbles appearing in the liquid
D. The temperature of the liquids changing

Answer 25

B. A solid appearing in the liquid

Question 26

A chemical change happens when . . .?
A. Glass breaks into pieces
B. Dough bakes in an oven
C. Ice cream melts into a liquid
D. Electricity flows through a wire

Answer 26

B. Dough bakes in an oven

Question 27

A potter knows that clay goes through a physical change whenever it becomes 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

Answer 27

B. Is the same substance as the wet clay

Question 28

Which shows an example of a physical and chemical change?
A. Boiling water and melting wax
B. Rusting iron and baking a cake
C. Dissolving powder and shredding paper
D. Freezing water and burning coal

Answer 28

D. Freezing water and burning coal