Phase Changes

Question 0

Adding heat energy to a solid causes _____________. Adding heat energy to a liquid causes _______________.

Answer 0

Melting, boiling (or vaporization)

Question 1

Removing heat energy from a gas to form a liquid is called ____________. Removing heat energy from a liquid to a solid is called _______________.

Answer 1

Condensation, freezing

Question 2

The water droplets on the outside of a cold drinking glass are caused by…

Answer 2

Condensation of the water vapor in the air- the cold glass removes heat from the vapor causing condensation.

Question 3

The plateau that is seen on a phase change graph shows that what happens during a phase change?

Answer 3

The temperature of the substance does not increase during a phase change. It stays the same until all of the substance has gone through the phase change.

Question 4

The melting point is the same as the _____________point.

Answer 4

Freezing

Question 5

The boiling point is the same as the ______________ point.

Answer 5

Condensation

Question 6

For what phase changes do molecules gain heat energy, move faster, and spread farther apart?

Answer 6

Melting and boiling (vaporization)

Question 7

In what phase changes do molecules lose heat energy, move slower, and move closer together?

Answer 7

Condensation and freezing

Question 8

Vapor changes to liquid-what phase chage?

Answer 8

Condensation

Question 9

Solid to liquid

Answer 9

Melting

Question 10

Liquid to solid

Answer 10

Freezing

Question 11

On a cold day you can see your breath. What phase change causes this to happen?

Answer 11

Condensation- the water vapor in your breath loses heat energy when it gets cold, so it condenses into liquid water droplets in the air.

Question 12

Liquid to gas

Answer 12

Boiling/vaporization/evaporaton

Question 13

If a substance’s melting point is above room temperature, then the substance will be in the ____________ phase.

Answer 13

Solid

Question 14

3 phases of matter

Answer 14

Solid, liquid, and gas