WATCH THE VIDEO TO LEARN MORE ABOUT WATER CHANGING STATES!

 

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TAKE THIS QUIZ TO PRACTICE WHAT YOU HAVE LEARNT.

SCORE AS WELL AS YOU CAN TO GET CLOSER TO THE MOON!


RECAP THE CONCEPTS

  • The water cycle provides living things with a continuous supply of fresh water.

  • The Sun is the main source of heat that causes water to evaporate from water bodies.

  • The water vapour rises to the sky, loses heat to the cooler surrounding air and condenses into tiny water droplets (clouds).

  • When the water droplets combine and become too heavy, they will fall back to the ground as rain.

 


When water gains heat:


MELTING

  • Occurs when solid water (ice) changes into liquid water.

  • When melting, ice gains heat but its temperature remains constant at melting point (0°C).


EVAPORATION

  • Occurs when liquid water changes into gaseous water (water vapour).

  • Water gains heat from its surroundings and evaporates.

  • This can occur at any temperature (between 0°C and 100°C).


Factors that affect the rate of evaporation include:

  • presence or strength of wind,

  • exposed surface area of water and

  • temperature of surroundings/water.


BOILING 

  • Occurs when liquid water changes into gaseous water (steam).

  • When boiling, water gains heat but its temperature remains constant at boiling point (100°C).

  • The white cloud observed above a pot of boiling water is made of tiny water droplets (not steam).


When water loses heat:


FREEZING 

  • Occurs when liquid water changes into solid water (ice).

  • It occurs at a constant temperature known as freezing point (0°C).

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CONDENSATION

  • Occurs when gaseous water (water vapour or steam) changes into liquid water (water droplets)

  • Water droplets form on the outer surface of a glass of cold water.

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  • Water droplets form on the inner surface of a glass of hot water.

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  • White clouds form above a pot of boiling water. This is because steam loses heat to the cooler surrounding air above the pot of boiling water and condenses to form water droplets.