How Water Changes States PC 3rd

Suppose it is a hot, sunny day. You have a cold glass of water filled with ice cubes. You notice that drops of water form on the outside of the glass. The drops from from water vapor in the air that has condensed on the cold glass. When water vapor loses heat energy, or cools, it changes to liquid water.

What is the change of a gas to a liquid called?

• evapoartion

• condensation

• melting

• freezing

When liquid water cools enough, it freezes. Freezing is the change of matter from a liquid to a solid. If liquid water loses enough heat energy, it becomes a sold- ice. Water freezes as 0 degrees Celsius, or 32 degrees Fahrenheit.

Which of these can cause liquid water to change to ice?

• heating it

• boiling it

• adding water vapor

• cooling it

Water vapor is a clear gas with no color. Water does not have to boil to evaporate. Evaporation can happen at different temperatures. It happens when water gets enough heat energy, or is heated enough. The liquid water becomes water vapor.

What happens to water when it evaporates?

• It becomes a solid

• It becomes drops

• It is no longer matter

• It becomes a gas in the air

When heat energy is added to sold ice cubes, they melt. The solid water becomes liquid.

Melting happens when

• liquid water changes to solid water

• liquid water changes to water vapor.

• solid water changes to liquid water.

• water vapor changes to liquid water.

When the air cools at night, drops of water called dew form on the grass.

How do the drops form?

• evaporation

• boiling

• freezing

• condensation

These drops of dew disappear during the day when the sun warms the air.

What causes the dew drops to disappear?

• freezing

• condensation

• evaporation

• melting