ice gas water
Water is commonly found as a solid, a liquid and a gas
(solid – ice / gas – vapour clouds / liquid – water)


  • a compound of the elements hydrogen and oxygen – water has the chemical formula H²O.
  • ice floats – because water is the only substance less dense (heavy) as a solid than a liquid water.
  • over 70% percent of the Earth’s surface is covered in water – this is why it looks blue from space.

Blue Planet

  • water is fundamental (basic) to all life – 72% of the human body is made up of water.

Human – 72% of water

  • our Earth is the only planet in the Solar System to have liquid water on its surface.

Earth only has liquid water on its surface.

  • Neptune has a deep ocean of ionized water beneath its atmosphere of helium and hydrogen.

Neptune’s atmosphere

  • dried-up riverbeds show that Mars probably once had water on its surface – there is ice both poles and probably underground as well. (Photo – Mars Panorama by Curiosity Rover)
  • a space probe found signs of frozen water on the Moon.

Lunar Frozen Water
(More information: wikipedia)


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