A Write the letter of the phrase that identifies each term.

1. B
2. H
3. L
4. E
5. A
6. G
7. D
8. J
9. K
10. C
11. M
12. F

B Write true or false in the space before each statement.

1. false
2. true
3. false
4. false
5. true
6. true
7. false
8. false
9. false
10. true

C Answer the questions about the pictures.

1. • Cirrus
   • Stratus
   • Cumulus
2. • Gas
   • Solid
   • Liquid

3. I'd say A (a dam) - if it isn't windy enough, B (a wind turbine) won't work. However, if there is ever a drought, A might not work either - it depends what A is connected to.

4. In the first picture, we can see some liquid water's molecules. In the second, we see solid ice's molecules. The water changed state by cooling down below or equal to 1°C.

5. B, it shows the atmosphere to be more dense closer to earth, due to gravity keeping the atmosphere close to the earth.

6. Friday, because the air is less dense and so has more room for water vapor.

E Write a short paragraph to answer each of the following.

Explain what takes place during the water cycle.

Say water starts in the ocean. Because of the heat around land, some water in the ocean evaporates. This water is now in the form of gas (or water vapor) which will form clouds when placed around enough other areas of water vapor. These clouds then form precipitation which either falls into the ocean directly, or onto the ground where it evaporates to water vapor. Either way, after this, the cycle restarts.

Describe how the following are formed:

Snow

The clouds in the air are cold enough and combine ice crystals in the cloud with air, which falls down as snow.

Hail

High up clouds form hail starting similar to snow, but as it falls, it is bounced up again by clouds, then repeats the process, wrapping more ice crystals around it.

Frost

The ground is so cold that water vapor condenses into ice on the grass, making frost.