The water cycle

• Water is found in the solid state in glaciers and ice sheets, in the liquid state in the oceans, rivers, lakes and aquifers and in the gas state in the atmosphere.
• Water cycles through the environment by processes that include melting, freezing, evaporation and condensation. Precipitation of water from the atmosphere can take the form of rain, sleet or snow.
• Life on Earth depends on water, on land and in the seas. Water acts as the solvent for chemical reactions in cells.
• It also helps transport dissolved compounds into and out of cells. Water is either a reactant or a product of biochemical changes such as respiration, photosynthesis and digestion.
• Rivers, lakes and seas provide habitats for many living organisms.