Matter Unit 2

1. The picture below shows Kelsey's glass of ice water. Which of the following is correct about Kelsey's glass of ice water?

A. It is a mixture because ice and water are two different things in two different states.
B. It is a mixture now because the water and ice can be seen in the glass, but it will not
be a mixture when the ice cubes melt.
C. It is not a mixture now because the ice is floating on the water, but it will be a
mixture when the ice cubes melt.
D. It is not a mixture because ice and water are the same substance in two different
states.

C. It is not a mixture now because the ice is floating on the water, but it will be a mixture when the ice cubes melt.

D. It is not a mixture because ice and water are the same substance in two different states.

B. It is a mixture now because the water and ice can be seen in the glass, but it will not be a mixture when the ice cubes melt.

In this scenario, the correct answer is A. It is a mixture because ice and water are two different things in two different states. When the ice cubes are in the glass with water, it forms a mixture of solid (ice) and liquid (water) phases.

Explanation

In this scenario, the correct answer is A. It is a mixture because ice and water are two different things in two different states. When the ice cubes are in the glass with water, it forms a mixture of solid (ice) and liquid (water) phases.

2. Which of the following describes the difference between the motion of liquid water and water vapor?

B. The motion of the particles is the same in both states, but they move slower in the gas state.

A. The particles in the liquid do not move, but the particles in a gas can move back and forth.

A. The particles in the liquid do not move, but the particles in a gas can move back and
forth.
B. The motion of the particles is the same in both states, but they move slower in the
gas state.
C. The particles in a gas can slide past each other, while the particles in a liquid are
locked in place.
D. The particles in a liquid can slide past each other, while the particles in a gas are free
to move in all directions.

C. The particles in a gas can slide past each other, while the particles in a liquid are locked in place.

In liquid water, the particles can slide past each other, allowing the liquid to flow and take the shape of its container. In water vapor, the particles are free to move in all directions as they are not confined like in a liquid state.

Explanation

In liquid water, the particles can slide past each other, allowing the liquid to flow and take the shape of its container. In water vapor, the particles are free to move in all directions as they are not confined like in a liquid state.

3. What is the most likely reason that the red liquid inside of a thermometer moves up when it is heated?

D. The particles in the red liquid move slower and spread apart.

A. The particles in the red liquid move faster and come together.
B. The particles in the red liquid move faster and spread apart.
C. The particles in the red liquid move slower and come together.
D. The particles in the red liquid move slower and spread apart.

A. The particles in the red liquid move faster and come together.

C. The particles in the red liquid move slower and come together.

When the red liquid inside a thermometer is heated, the particles in the liquid gain energy and move faster, causing them to spread apart. This expansion leads to an increase in volume, which in turn causes the liquid level to rise in the thermometer.

Explanation

When the red liquid inside a thermometer is heated, the particles in the liquid gain energy and move faster, causing them to spread apart. This expansion leads to an increase in volume, which in turn causes the liquid level to rise in the thermometer.

4. Elizabeth has two separate samples of the same substance. One sample is in the liquid state, and the other is in the solid state. The two samples most likely differ in which property?

A. the chemical bonds between atoms within the substances
B. the types of atoms that are found within the substances
C. the motion of the atoms within the substances
D. the size of the atoms within the substances

B. the types of atoms that are found within the substances

C. the motion of the atoms within the substances

D. the size of the atoms within the substances

The answer is A because the main difference between a substance in liquid and solid state lies in the arrangement and strength of the chemical bonds between atoms.

Explanation

The answer is A because the main difference between a substance in liquid and solid state lies in the arrangement and strength of the chemical bonds between atoms.

5. Which of the following is an example of a container that is filled with a pure substance rather than a mixture?

B. a jar filled with salt water

D. a glass filled with chocolate milk

A. a tire filled with air

A. a tire filled with air
B. a jar filled with salt water
C. a balloon filled with helium
D. a glass filled with chocolate milk

Helium is an element and a pure substance, making a balloon filled with helium an example of a container with a pure substance. Options A, B, and D contain mixtures of different substances.

Explanation

Helium is an element and a pure substance, making a balloon filled with helium an example of a container with a pure substance. Options A, B, and D contain mixtures of different substances.

6. Which of the following statements describes a difference between a mixture and a pure substance?

A. A mixture tends to be homogeneous, while a pure substance tends to be
heterogeneous.
B. A mixture has a specific melting point, while the melting point of a pure substance
can vary.
C. The density of a mixture can change with temperature, but the density of a pure
substance cannot change.
D. The composition of a mixture can vary from sample to sample, but the composition of
a pure substance is always the same.

C. The density of a mixture can change with temperature, but the density of a pure substance cannot change.

A. A mixture tends to be homogeneous, while a pure substance tends to be heterogeneous.

B. A mixture has a specific melting point, while the melting point of a pure substance can vary.

A pure substance has a fixed composition, meaning its properties remain constant regardless of sample. On the other hand, a mixture can have varying compositions, leading to differences in properties between samples.

Explanation

A pure substance has a fixed composition, meaning its properties remain constant regardless of sample. On the other hand, a mixture can have varying compositions, leading to differences in properties between samples.

7. On a warm sunny afternoon, ocean water splashed onto a rock. A short time later, the rock was dry. Which statement best explains what happened to the water on the rock?

C. Salt caused the water to become a gas.

A. Heat caused the water to become a gas.
B. Heat melted the water and it disappeared.
C. Salt caused the water to become a gas.
D. Salt melted the water and it disappeared.

B. Heat melted the water and it disappeared.

D. Salt melted the water and it disappeared.

The correct answer is A. Heat caused the water to become a gas. When the warm sun's heat was applied to the water on the rock, it caused the water to evaporate and turn into gas, leading to the rock becoming dry.

Explanation

The correct answer is A. Heat caused the water to become a gas. When the warm sun's heat was applied to the water on the rock, it caused the water to evaporate and turn into gas, leading to the rock becoming dry.

8. If a certain mixture is homogeneous, you would probably conclude that the physical properties and the composition:

B. vary smoothly from the top to the bottom of the sample

D. are visibly different throughout the sample

A. are different from one part of the sample to another
B. vary smoothly from the top to the bottom of the sample
C. are the same in every small volume from the sample
D. are visibly different throughout the sample

A. are different from one part of the sample to another

In a homogeneous mixture, the physical properties and composition are uniform throughout, hence the correct answer is that they are the same in every small volume from the sample.

Explanation

In a homogeneous mixture, the physical properties and composition are uniform throughout, hence the correct answer is that they are the same in every small volume from the sample.