Unit 7 Review: Water

Here is a quiz about the water unit. At the end you can find the answers.

Water (review) from David Santos

The three states of water

THE THREE STATES OF WATER

Water exists in three states: liquid, solid and gas.

• Rain, rivers and oceans are examples of water in a liquid state.
• Ice, snow and hailstones are examples of water in a solid state.
• Water vapor is a gas.

Water can change states.

Water changes from one state to another when it's temperature changes.

• When liquid water is cooled to below 0°C, it changes into ice. This is solidification.
• When ice is heated, it changes into liquid water. This is melting.
• When liquid water is heated, it changes into water vapor. This is evaporation.
• When water vapor cools, it changes into liquid water. This is condensation.

The Water Cycle

THE WATER CYCLE

1. 1  From the oceans to the clouds 
   
   Water is continually moving around the Earth. This causes the water cycle.
   The water cycle begins when water from the oceans, lakes and rivers heats up and evaporates to form water vapor. Water vapour passes into the cold atmosphere. The cold temperature makes the water vapour cool down and condense. Condensed water in the atmosphere turns into tiny water droplets and forms clouds. Clouds move across the sky with the wind.
   
   
2. 2  From the clouds to the land
   
   As clouds move across the sky, the tiny water droplets in the clouds join together to form larger drops. These large drops of water fall to the land as rain. When rain freezes, it falls to the land as snow or hail.
   
   
3. 3  From the land to the sea
   
   When rain falls on the land, it forms streams. Streams flow into rivers. Rivers flow into seas and oceans. When snow melts, it flows into the streams and rivers and finally reaches the sea. Sometimes, rainwater and melted snow sink deep into the ground to form aquifers. Water from wells and springs comes from aquifers.