Phase Change Lesson

A chef finds a sealed container consisting of an ingredient that goes into his restaurant’s secret sauce. The ingredient’s molecules are moving in place. What will happen if the chef causes the ingredient to change phase by transferring energy into it?

After the phase change, the ingredient’s molecules will move . . .

• faster, and the ingredient will be a solid.

• faster, and the ingredient will be a liquid.

• slower, and the ingredient will be a solid.

• slower, and the ingredient will be a liquid.

Tags

NGSS.MS-PS1-4

The image above shows information about two different substances in sealed containers. A scientist transfers the same amount of energy into both substances. One substance changes phase, but the other does not. Which chemical changed phase, and why did it change?

• Substance A changed phase because its molecules were able to move fast enough to overcome the attraction between them. It is now a gas.

• Substance A changed phase because the weak attraction between its molecules allowed them move faster. It is now a gas.

• Substance B changed phase because the molecules were able to move fast enough to overcome the attraction between them. It is now a gas.

• Substance B changed phase because the strong attraction between molecules made their movement slower. It is now a solid.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-5

A student left a jar of water outside his home. Water can be a solid, liquid, or gas. When he put the jar outside, the water was liquid. Twelve hours later, the water had changed phase and was a gas. What happened to the water molecules?

• When the student left the jar outside, the molecules were moving around each other. Later, the molecules were moving in place.

• When the student left the jar outside, the molecules were moving away from each other. Later, the molecules were moving around each other.

• When the student left the jar outside, the molecules were moving in place. Later, the molecules were moving around each other.

• When the student left the jar outside, the molecules were moving around each other. Later, the molecules were moving away from each other.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

NGSS.MS-PS3-5

What takes place when a liquid changes to a gas?

• condensation

• melting

• evaporation

• freezing

Tags

NGSS.MS-PS1-4

Study the diagram below. The material begins to condense at point:

• 1

• 2

• 3

Tags

NGSS.MS-PS1-4

What takes place when a solid changes to a liquid?

• condensation

• freezing

• melting

• evaporation

Tags

NGSS.MS-PS1-4

What takes place when a solid changes to a liquid?

• condensation

• melting

• evaporation

• freezing

Tags

NGSS.MS-PS1-4

An Earth scientist brought an unknown substance from underground back to her lab. The substance was in the gas phase and was put into a sealed tank as shown above. She slowed down the molecules inside the tank and the substance changed phase. How did she do this, and how did it affect the molecules?

She transferred energy . . .

• into the substance, and the molecules moved around each other.

• into the substance, and the molecules moved away from each other.

• out of the substance, and the molecules moved around each other.

• out of the substance, and the molecules moved in place

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-5

All phase changes (changes of states) require energy to be added or taken away.

• True

• False

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

Scientists have a container of water. Water can be a solid, liquid, or gas. At first, the water molecules in the container were moving around each other. Later, the water molecules were moving in place. What change did the scientists observe?

• At first, the water was a gas. After, it was a liquid.

• At first, the water was a solid. After, it was a liquid.

• At first, the water was a liquid. After, it was a gas.

• At first, the water was a liquid. After, it was a solid.

Tags

NGSS.MS-PS1-4