Phase Change End of Unit

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

A scientist has a container with a substance inside.  At first, the molecules in the substance move away from each other. Later, the molecules move around each other. What change did the scientist observe in the substance?

• Before, the substance was a liquid. Later, it was a solid.

• Before, the substance was a gas. Later, it was a liquid.

• Before, the substance was a liquid. Later, it was a gas.

• Before, the substance was a solid. Later, it was a liquid.

Tags

NGSS.MS-PS1-4

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

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

• 1

• 2

• 3

Tags

NGSS.MS-PS1-4

A cook had a jar containing a sweet food and a jar containing a sour food. The image above shows the sweet and sour foods. At room temperature, both foods are liquids. The same amount of energy was transferred into both substances. Later, one of the foods had changed phase while the other had not. Which food changed phase, and how did it change?

• The sweet food changed because the molecules were able to move fast enough to overcome the attraction between them. Its molecules now move away from each other.

• The sweet food changed because the strong attraction between molecules made their movement slower. Its molecules now move around each other.

• The sour food changed because the weak attraction between molecules let them move faster. Its molecules now move away from each other.

• The sour food changed because the molecules were able to move fast enough to overcome the attraction between them. Its molecules now move in place.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

NGSS.MS-PS3-5

Mario is making chocolate. In part of the chocolate-making process, he changed the phase from a liquid to a solid. What happened to the molecules of chocolate when it changed phase?

• Before changing phase, the molecules were moving around each other. After changing phase, they were moving away from each other.

• Before changing phase, the molecules were moving around each other. After changing phase, they were moving in place.

• Before changing phase, the molecules were moving away from each other. After changing phase, they were moving around each other.

• Before changing phase, the molecules were moving in place. After changing phase, they were moving around each other.

Tags

NGSS.MS-PS1-4

Scientists put a sample of water into a sealed tank. Water can be a solid, liquid, or gas. 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

A scientist has two substances that she is testing in her lab: a pink substance and a green substance. At room temperature, both substances are liquids. The scientist transferred the same amount of energy into both substances. She finds only the pink substance changed phase. How is the pink substance different from the green substance? The pink substance has a . . .

• weaker attraction between its molecules than the green substance. Its molecules now move away from each other.

• weaker attraction between its molecules than the green substance. Its molecules now move in place.

• stronger attraction between its molecules than the green substance. Its molecules now move away from each other.

• stronger attraction between its molecules than the green substance. Its molecules move around each other.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

NGSS.MS-PS1-2

The diagram above describes the movement of molecules in a substance used to make fuel. What change did the fuel scientist observe in the substance?

• Before the process, the substance was a solid. After the process, it was a liquid.

• Before the process, the substance was a gas. After the process, it was a liquid.

• Before the process, the substance was a liquid. After the process, it was a solid.

• Before the process, the substance was a liquid. After the process, it was a gas.

Tags

NGSS.MS-PS1-4