Original Project
Weather and Climate I: Basic Elements
Clouds and rain form as air cools and water vapor in the air condenses into water droplets.
Item WC080003: Rain forms as the air in a cloud cools, causing tiny water droplets to form and combine to form larger droplets.
Which of the following statements describes what happens that makes rain start to fall from a cloud?
- Air must cool to form a pool of water in a cloud, and wind must blow on the cloud for droplets to form and to fall from the cloud.
- There is always a pool of water inside a cloud, and if the wind blows hard enough it blows the water out of the cloud, but the air in the cloud does not have to cool to cause water droplets to fall from the cloud.
- Air must cool to form more and more water droplets inside a cloud. The droplets then collect together until they are heavy enough to fall. Wind does not have to blow on the clouds to cause water droplets to fall from the cloud.
- Air does not have to cool to form water droplets, and wind does not have to blow on a cloud for rain to fall. The only time that water droplets fall from clouds is when the pool of water in a cloud is too big for the cloud to hold.
- Distribution of Responses
- Students Responding Correctly
| Group | Correct | Total | Percent |
|---|---|---|---|
| Overall | 974 | 2575 | 38% |
| Grades | |||
| 6–8 | 557 | 1581 | 35% |
| 9–12 | 417 | 994 | 42% |
| Gender | |||
| Male | 468 | 1239 | 38% |
| Female | 489 | 1281 | 38% |
| Primary Language | |||
| English | 876 | 2303 | 38% |
| Other | 73 | 210 | 35% |