4 th Grade Science

Objectives Describe the different stages of the water cycle Draw a diagram of the water cycle Explain the importance of the water cycle

Quiz 1 1. What are clouds made of? 2. Do we have an unlimited amount of water on the earth? 3. How old is the water on the earth right now?

Answers to Quiz 1 1. Clouds are made of water in the form of vapor. When clouds get enough water vapor they produce rain. 2. There is a limited amount of water on the earth. That is why we have a water cycle. 3. The water on the earth right now is the same water that has always been on the earth. It just keeps going through the water cycle over and over again.

Introduction to the water cycle The earth does not get new water every time it rains. That rain is actually the same water that was in a puddle or an ocean a several days. So how does water go from being in an ocean to falling down as rain? The answer is the water cycle. There are four parts to the water cycle: evaporation, condensation, precipitation and collection. The water cycle is important because the earth only has so much water on it and we need to be able to reuse it over and over again. Watch me >

The four stages of the water cycle

Stage 1: Evaporation This is when the sun heats up water in puddles, lakes, rivers and oceans. When the water gets heated up in turns into water vapor or steam. Have you ever seen the road have steam coming off of it after it rains? That is evaporation. The same thing can happen on lakes and rivers.

Stage 2: Condensation This is when the air cools the water vapor and forms clouds.

Stage 3: Precipitation Eventually, so much water forms in the clouds that the air can no longer hold it up. When this happens the water falls back to earth. The water can be in the form of rain, hail, sleet or snow depending on the temperature of the air.

Stage 4: Collection Some of the precipitation falls directly back into rivers, lakes or oceans. There it is ready to begin the cycle all over again. However, some of the precipitation falls on land. When this happens it is either soaked into the ground and becomes part of the ground water that plants use or it runs over the land and back into rivers, lakes and oceans.

Quiz 2 1. Which is a picture of evaporation?

Quiz 2 2. How many stages are in the water cycle? 3. How are clouds formed?

Answers to quiz There are four stages to the water cycle. 3. Clouds are formed when water vapor cools in the air

Homework Draw and label a diagram of the water cycle. The diagram should include all four stages of the water cycle. 1. Evaporation 2. Condensation 3. Precipitation 4. Collection

A Quick Review EvaporationCondensationPrecipitation Collection