making rain science corner week2

Document Sample
making rain science corner week2 Powered By Docstoc
					Science Laboratory

Making Rain

Water in nature is always moving – rising up to form clouds and then coming down again as rain. Simulate the water cycle with a kettle, pot, and some ice water!

Materials: Kettle; small saucepan; shallow pan; water; ice cubes. Instructions: 1. This activity should be done with adult supervision. 2. Heat some water in a kettle. 3. Put some cold water and ice cubes into a saucepan. 4. When the water in the kettle is boiling, hold the saucepan full of cold water just above the steam. 5. Keep your hands out of the steam because it can cause severe burns!!! 6. Watch water droplets form on the bottom of the saucepan. Some of the droplets will become large enough to drip off. When this happens, it is raining! 7. Observe your experiment, note down your discoveries and answer the following questions on the science observation sheet.

Frédéric Bédard INTENSIG – SPEAQ convention 2007

Name:________________ Date:___________________ Science Observation Sheet
(name of the experiment):__________________________

Consult your partners and answer the following questions as you observe the experiment.

1. How is your model of rain like the water cycle? ______________________________________________________________ ______________________________________________________________ ______________________________________________________________

2. What does the kettle of boiling water represent? ______________________________________________________________ ______________________________________________________________ ______________________________________________________________

3. How can you make a rain shower develop more quickly? ______________________________________________________________ ______________________________________________________________ ______________________________________________________________

4. Can you affect the size of the drops that fall from the saucepan? ______________________________________________________________ ______________________________________________________________ ______________________________________________________________

Frédéric Bédard INTENSIG – SPEAQ convention 2007

When lakes, oceans and rivers are heated by the sun, invisible water vapour rises into the air (some of the water turns from a liquid to a gas). This is evaporation. There are a number of factors that affect evaporation. The hotter water gets, the faster its molecules move, and the faster it evaporates. When a greater surface area of water is exposed (e.g. shallow pan of water containing the same volume of water as a drinking glass), the water evaporates faster because more of it is in direct contact with the air. Finally, wind makes water evaporate faster because it pushes molecules on the water’s surface into the air faster.

As water vapour rises, it cools and condenses into tiny droplets of water around microscopic particles floating in the air. Billions of particles with water droplets form a cloud. Precipitation occurs when droplets combine and become so heavy that air currents can no longer hold them up. Or, as a cloud grows and reaches up into the higher, colder parts of the atmosphere, some droplets turn to ice. The ice crystals grow at the expense of liquid droplets, which are attracted to the ice and freeze on it. The ice crystals eventually become too large to be held up by air currents, and begin to fall. Depending on the temperature near the ground, the moisture from clouds falls as either rain, snow, or sleet. Much of the precipitation that falls on land eventually flows back into lakes and oceans. So, the cycle continues.

Frédéric Bédard INTENSIG – SPEAQ convention 2007

Shared By:
Description: Handouts and worksheets for teachers