Water-A Precious Resource Notes

• Water is a natural resource that is vital for both plants and animals.
• Water is the most abundant component on Earth’s surface.
• 70%-75% of Earth’s surface is covered by water.
• Most of the water that exists on Earth is in the seas and oceans.
• Sea and ocean water is highly salty and hence unfit for drinking. Most of the fresh water is frozen in the glaciers and in the polar ice caps, and is thus not readily available.

Diagrammatic representation of water on the Earth

• Water exists in three states i.e., solids, liquids, and gases.
• All the three states are reversible or interchangeable.
• All the three states of water are present in our natural environment at any given time.

Forms of water

• The continuous circulation of water in nature is called water cycle. It is also called the hydrological cycle.

Water cycle

• There are six important processes that make up the water cycle.

Condensation:

• The opposite of evaporation. Condensation occurs when vapour is changed into a liquid.

Infiltration: