Book 7, Question 15
Why Does Steam Rise From a Hot Sidewalk After Rain?
When rain falls on hot pavement, the water can start to rise again right away. The sidewalk is much warmer than the rain, so the leftover water heats up quickly. It turns into vapor, and you see a soft steam-like curtain rising.
From the book
Page from A Million Whys Book 7
More fun facts
- Heat makes water molecules jiggle so hard that some break their bonds and escape into the air as water vapor.
- That is why water dries up faster on a hot surface.
- Water vapor is the most common greenhouse gas. It causes about half of Earth's greenhouse effect.
- Without greenhouse gases, Earth's surface would be about 59 degrees Fahrenheit colder.
- Warmer air holds more water vapor, so a warming climate means more water vapor in the air.
- NASA satellites make maps that show how much water vapor is in the air around the world each month.
Sources: Science News Explores, NASA Science, NASA Science
Questions kids ask
Why does water dry faster on hot ground?
Heat gives water molecules extra energy so more of them escape into the air.
Is water vapor a greenhouse gas?
Yes. It causes about half of Earth's greenhouse effect.