Water: Movement, Change, and Energy
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Water: Movement, Change, and Energy
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What do you already know about the forms of water on Earth and in the air?
Learning Objective
At the end of the lesson you will understand how water moves on Earth and in the atmosphere, and how crystallisation, evaporation, and kinetic energy drive these changes.
Where Is Water Found on Earth?
Water exists in oceans, lakes, rivers, underground, and in the atmosphere as vapour. It is vital for life.
States of Water
Water can be found as a solid (ice), a liquid, or a gas (water vapour). Changes between these states involve changes in energy.
Evaporation and Crystallisation
Evaporation happens when liquid water turns into vapour due to heat from the Sun.
Evaporation
Crystallisation
Crystallisation occurs when water vapour cools and forms ice or snow, arranging molecules into a crystal structure.
Kinetic Energy and Water
Kinetic energy is the energy of movement. When water molecules move faster, they can escape as gas (evaporation); when they slow down, they may freeze (crystallisation).
The Water Cycle
The water cycle describes how water moves through evaporation, condensation, precipitation, and crystallisation, linking Earth's surface and atmosphere.
Reflect: Water Changes Around You
Think of examples where you see water changing state (evaporating, freezing, or melting) in daily life. Why do these changes happen?
Write down 3 things you learned in this lesson.
Write down 2 things you want to know more about.
Ask 1 question about something you haven't quite understood yet.