The Importance Of Water To Life

Life as we know it can not exist without water. Seventy-five % of the Earth is covered in water providing an environment for organisms to live in. the water molecule is made up of two hydrogen atoms and one oxygen atom. As oxygen atoms are more electronegative that hydrogen atoms the electrons shared covalently between the oxygen and the hydrogen atoms tend to spend more time near the oxygen atom making it partially negative and making the hydrogen atoms partially positive. The partial charges in the water molecule allow it to form weak or hydrogen bonds with other water molecules. The hydrogen bonds between water molecules cause the water molecules other properties like cohesion, adhesion, surface tension, waters ability to retain heat, and its ability to dissolve polar or ionic substances.

Cohesion and adhesion are some of water's unique properties. These properties allow water to travel up plant stems; cohesion makes the water molecules stick together and adhesion makes the water cling to the stem wall therefore counteracting the downward pull of gravity. Without these properties, water would not reach all cells in a plant as a result the plants could not photosynthesize it and could not release oxygen causing almost all life forms to perish.

Water makes up 75% of the Earth as well as 70-95% of most cells. Water's ability to retain large amounts of heat with only a slight change in its own temperature is an essential property to ensure life on Earth. The vast bodies of water retain enormous amounts of heat during the day which insures survival for marine life. The water gradually cools during the night releasing its heat into the air making waterfront areas have warmer climates. As a result, water's high specific heat regulates temperature on land and water to limits that allow life.

Although most substances become denser as a solid due to the atoms rigid structure, water becomes less dense. As water molecules cool down they form a crystal lattice were the hydrogen bonds keep the water as far away from each other as possible making ice 10 times less dense than liquid water and allowing ice to float. When immense bodies of water are frozen ice forms a top layer and protects the water under