science ch 2 les 2.2

Apuntes

• Water Cycle: In the water cycle, water moves continuously from Earth's surface to the atmosphere and back. **Identify:** As you read, label the three processes of the water cycle in the diagram. **Evaporation:** How does water from the ground get into the air? The process by which molecules of liquid water absorb energy and change to a gas is called evaporation. The energy for evaporation comes from the heat of the sun. In the water cycle, liquid water evaporates from oceans, lakes, and other sources, forming water vapor, a gas in the atmosphere. Smaller amounts of water also evaporate from living things. Plants release water vapor from their leaves. Humans release liquid water in their wastes and water vapor when they breathe. **Condensation:** As water vapor rises higher in the atmosphere, it cools down. The cooled vapor then turns back into tiny drops of liquid water. The process by which a gas changes to a liquid is called condensation. The water droplets collect around dust particles and form clouds. **Precipitation:** As more water vapor condenses, the drops of water in the clouds grow larger. Eventually, the heavy drops fall to Earth as precipitation—rain, snow...