Water is all around us, even when we do not always notice it. We see water in rain, puddles, rivers, lakes, and the sea. Plants, animals, and people all need water to live.
Learning where water is found helps young scientists observe the world carefully.
Key Facts
- Water is made of tiny particles called molecules, and its formula is H2O.
- Water can be a liquid, a solid called ice, or a gas called water vapor.
- Liquid water takes the shape of its container.
- Ice forms when water gets very cold, usually at 0°C or 32°F.
- Water vapor forms when liquid water warms up and evaporates.
- The water cycle moves water through evaporation, condensation, and precipitation.
Vocabulary
- Water
- Water is a clear liquid that living things need and that can also become ice or vapor.
- Liquid
- A liquid is a form of matter that flows and takes the shape of its container.
- Ice
- Ice is frozen water that is solid and keeps its own shape.
- Water vapor
- Water vapor is water in gas form that can be found in the air.
- Rain
- Rain is liquid water that falls from clouds to the ground.
Common Mistakes to Avoid
- Thinking water is only found in cups or bottles. Water is also found in clouds, rain, rivers, oceans, plants, animals, and the air.
- Calling ice something different from water. Ice is still water, but it is in solid form because it is cold.
- Thinking water vapor is the same as smoke. Water vapor is water in gas form, while smoke comes from burning materials.
- Forgetting that water can change form. Heating and cooling can change water between liquid, ice, and vapor.
Practice Questions
- 1 A child sees 3 puddles after the rain and then finds 2 more puddles near the playground. How many puddles does the child see in all?
- 2 There are 4 ice cubes in a cup. A student adds 5 more ice cubes. How many ice cubes are in the cup now?
- 3 A wet towel is left in the sun and becomes dry later. Explain what happened to the water in the towel.