- Possible Questions
- Students will learn about the effects of rain/water and how water is essential for life.
Precipitation (part of the water cycle; see Unit 4: Lesson 1) in the form of rain occurs when particles of water are large enough to reach the ground. The chief difference between a cloud drop and a rain drop is size. It takes many cloud droplets to make up a single raindrop. Raindrops can be produced by the collision and merging of cloud droplets. Large droplets fall faster and merge with smaller ones. When two rain droplets merge, “coalescence” has taken place. As a result of coalescence, the large drops can grow fairly rapidly.
- Bucket of loose soil
- Buckets of water
- Cups for pouring water
- Dehydrated: deprived of water
- Precipitation: rain, hail, sleet or snow, all of which are formed by condensation of moisture in the atmosphere and fall to the ground when so much water has condensed that the air cannot hold it anymore
Prepare paper slips with rain riddles, one for each student (see below). Be sure that there is both a riddle and an answer, each with its own number. Fill a bucket with loose soil. (Have the students help dig up the dirt.)
Each number is written on a different slip:
- If rain drops are very small, they are collectively termed.
- Rain plays a key role in the.
- water cycle.
- Raindrops are formed when tiny droplets in clouds are.
- ______ is a shortage of rain over an extended period of time, resulting in a water shortage for some activity, group, or environmental sector.
- Rain falls about.
- 30 kilometers per hour (19 mph).
- It takes aboutcloud droplets to provide enough water for one raindrop.
- one million
- By average annual rainfall, the wettest place in the world is _____.
- Mawsynram, India
- 2.5 centimeters (1 in) of rain water is equivalent toof snow on the white mountain caps.
- 38.1 centimeters (15 in)
- Water is found naturally in three forms:.
- liquid, solid, and gas.
- You have 15 billion brain cells, which are between.
- 74 percent and 85 percent water.
- You could live for a month without food, but you would be dead after a week without.
- If you feel thirsty, you’re probably already.
- Experts agree that to stay healthy, energized and fully alert, we need to drink at leastglasses of water a day.
- Aboutof your body is water.
- 77 percent
- There is the same amount of water on Earth as there was when Earth was formed. The water from your faucet could contain molecules that _____ drank.
- Water boils atCelsius.
- 100 degrees (212° F)
- Water freezes atCelsius.
- 0 degrees (32° F)
- Human bones arewater.
- 25 percent
- Human blood iswater.
- 83 percent
- Water regulates Earth’s.
- Water expands bywhen it freezes.
- 9 percent
- Frozen water (ice) is lighter than water, which is why icen water.
Each child gets one paper slip. They walk around reading their papers to each other and trying to find their partner. For example: The child with the slip that has “Water freezes at _____ Celsius” should find the child with the slip that says 0 degrees. Once they think they have found their partner, have them move away from the others to a certain spot. Once all (or most) partners are found, have the children read their facts. It isn’t important that they are all correct. The teacher can make any corrections along the way. The purpose is to activate new knowledge about rain and water and get the students interested.
Now begin the experiment.
Spread some of the loose soil in a small area. A sloped surface works best and can be created by tipping a table top or placing a rock under one end of a board. If you’re lucky to have a sloped piece of land nearby, that would work well.
Starting at the top edge of the slope, allow children to drip water from their fingers like a light rain. Increase the amount and pressure of water as the experiment continues. (Replace soil as necessary from the bucket.) The final time should be the largest amount of water thrown or poured from a big height for force.
Run the experiment again, but this time, dig up some small clumps of grass and plant them in the soil. Have the students compare the results of water flowing on bare ground with some ground containing grass.
At each stage, ask questions such as the following:
- What processes are going on (e.g., gravity, erosion, or resistance)? Gravity pulls water down a hill. Erosion is the deterioration of the soil as water carries it away.
- Note that, in nature, vegetation provides resistance and slows water. Less erosion takes place as leaves diminish the force of falling water and roots hold the soil. What would occur if all the vegetation were destroyed in a forest fire?
- What physical processes are acting on this area?
- What could be the effect of a heavy rainfall in this area?
- What could be the effect if we added more vegetation to this area?
- What could be the effects if cattle or goats overgrazed this area or if there were a grass fire?
Rain/Water is an important part of life. Without water, plants wouldn’t grow and animals would either move to areas with water or die. Rain has many benefits, but can also cause erosion. Vegetation (because of the roots) helps soil to stay in place.
- Describe what happened when different amounts of water were poured. What about different amounts of force?
- What do you see before, during, and after storms?
- What types of rain are most beneficial? Damaging?
- List all of the uses for water.
- What is the most important resource on Earth? Why do you think so?
- How are puddles formed? Why do puddles disappear?
- Is rain ever harmful to us or to animals?
- What would happen if it stopped raining?
1. Before and After
Have students fold a sheet of paper in half. Label one side Before and one side After. On one side have them draw a picture before it rains. On the other have them draw a picture after it rains. In their second drawing, have students consider the amount of rain that fell and the force with which it fell. Their pictures may show benefits or rain, or problems created by rain.
2. “Where’s the Water?” Scavenger Hunt
Objective: To find evidence of water and water’s influence around us.
Materials: Scavenger card (list of things to look for). Make the list simpler for younger students. Increase the number of each type of item for older students. Examples: two things that store water, somewhere water goes, something water has changed, three different things that drink water, something that water helps grow.
Using a scavenger card, students are asked to find various effects of water. Upon returning, students can share their responses and be led in a discussion about the importance of water in shaping our environment.