Unit 1 Water Cycle 水循环 | 4thgradeimmersion

Water Cycle 水循环

Objective

1. I can describe the relationship between heat energy, evaporation and condensation of water on Earth.

2. I can describe the water cycle.

1.1 The water on the earth

💧 75% of the surface of the earth is water. Without water we could not survive.

💧The water on the earth could be catergorized as salt water(ocean, 97%), glaciers(2%), and fresh water(primary source of drinking water, 1%).

💧 The amount of water has stayed the same over eons of years. However, the form or state of water keeps changing.

1.2 Three forms of water

💧 There are three forms of water: solid, liquild, and gas.

💧 Solid water, ice , is frozen water. water freezes at 0° C /32° F.

💧 Liquid water is wet and fluid.

💧 Gas water, vapor, is always in the air around us. liquid water changes to vapor at 100° C/212°F.

1.3 Essential process in water cycle .

💧Evaporation 蒸发: The process that occurs when water changes from a liquid to a gas, caused by heat.

💧 Condensation 凝结 : The cooling of water in the atmosphere changing gas to a liquid.

💧Precipitation 降水 : Water droplets fall from the atmosphere in the form of rain, sleet, snow, or hail.

💧Transpiration 蒸腾 : The passage of water vapor from a plant to the atmosphere.

💧 Run-off 径流：Rainfall that is not absorbed by soil and travels to the ocean.

Are you ready for the unit test?

1.Where is most of Earth’s water located? What is the percentage?

2.What is evaporation? What is condensation? What is precipitation?

3. What are the steps as water moves through in the water cycle?

4. What is the source of energy for the water cycle?

5. Explain why evaporation would occur more quickly in St. George during the summer than in Salt Lake during the winter.

The temperature is different; it is hot in St. George in summer and cold in Salt Lake City in winter.

6. How might water from an ocean end up on a field in Utah?

Water evaporates from the ocean, is carried by wind as water vapor to Utah and condenses and falls as rain.