Test Review: Phase Changes

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

• Before the student left, the molecules were moving in place. After, the molecules were moving around each other.

• Before the student left, the molecules were moving around each other. After, the molecules were moving away from each other.

• Before the student left, the molecules were moving around each other. After, the molecules were moving in place.

• Before the student left, the molecules were moving away from each other. After, the molecules were moving around each other.

Tags

NGSS.MS-PS1-4

Lily is doing a science experiment with a substance in a sealed jar. At first, the substance’s molecules are moving around each other. What will happen to Lily’s substance if she transfers energy into the substance and causes a phase change? After the phase change, the substance’s molecules will move . . .

• faster, and the substance will be a liquid.

• faster, and the substance will be a gas.

• slower, and the substance will be a solid.

• slower, and the substance will be a liquid.

Tags

NGSS.MS-PS1-4

Anh measured the temperature of a pond near his house. Before he left for school, the water in the pond was 18°C. When he came home from school, the temperature of the pond was higher than it was in the morning. What happened to the water molecules while he was at school?

• The molecules got closer together.

• The molecules started moving faster.

• The water lost cold molecules.

• The molecules became larger.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-5

NGSS.MS-PS3-4

Scientists digging in a cave found an unknown substance. The scientists found that the substance’s molecules were moving around each other. The scientists increased the speed of the substance’s molecules and caused a phase change. How did the scientists do this, and how did this affect the substance? The scientists transferred energy . . .

• into the substance, and the substance changed into a gas.

• into the substance, and the substance changed into a liquid.

• out of the substance, and the substance changed into a solid.

• out of the substance, and the substance changed into a liquid.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-5

What happens to molecules when their kinetic energy decreases?

• They move slower.

• They move faster.

• They get heavier.

• It depends on the type of molecules.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-5

NGSS.MS-PS3-4

During a cold winter night, a glass of water was left outside. In the morning, the water had turned into ice. What happened to the water molecules?

• The molecules started moving around each other.

• The molecules moved slower and got closer together.

• The molecules became larger.

• The molecules moved faster and spread apart.

Tags

NGSS.MS-PS1-4

A scientist observed a beaker of liquid on a hot plate. As the temperature increased, the liquid began to boil. What happened to the molecules in the liquid?

• The molecules became smaller and denser.

• The molecules moved faster and turned into a gas.

• The molecules moved slower and formed a solid.

• The molecules stopped moving completely.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-5

What is the effect on the molecules of a substance when it is cooled down significantly?

• The molecules start to vibrate more intensely.

• The molecules become lighter.

• The molecules move faster and spread apart.

• The molecules move slower and get closer together.

Tags

NGSS.MS-PS1-4

Molecules are like people because when the temperature increases...

• They will join together

• They will move away from each other

• They do nothing

Tags

NGSS.MS-PS1-4

Scientists water into a sealed tank. At first, the water was a liquid. Then, the scientists transferred energy out of the substance, and the water changed phase. What happened to the movement of the water molecules?

After the phase change, the water molecules moved . . .

• faster and started moving away from each other.

• faster and started moving around each other

• slower and started moving in place

• slower and started moving around each other.

Tags

NGSS.MS-PS1-4