Water

                                                                               Water

Water structures :

The molecular formula of water is H2O.

The water molecule contains 2 hydrogen atoms and 1 oxygen atom. The hydrogen and oxygen atoms are held together by covalent bonds.

As the water molecule has two opposite poles, it acts like of a magnet and therefore water is a polar compound.

Properties of water:

Cohesion: Cohesion is an attraction between molecules of the same substance.

Example : ocean , rivers 

Adhesion:  Adhesion is an attraction between molecules of different substances

Example: water on a window

 

High surface tension: a measure of hard it is to break the surface of a liquid

Capillary action : when liquid flows through narrow spaces without external forces, such as gravity

A meniscus is a curve formed on the upper surface of a liquid inside a container because of cohesion and adhesion.

Heat capacity: Water has high heat capacity because the amount of heat energy required to increase water’s temperature is relatively high.

Example: Large bodies of water, such as oceans and lakes, can absorb large amounts of heat with only small changes in temperature.

The high heat capacity of water helps to keep the body temperature constant.

Changes in density: Water density changes with temperature and salinity 

Universal solvent : Water is “Universal Solvent” because water can dissolve many substance like polar and ionic substances

Facts about water : 

Water is an inorganic compound with the chemical formula H2O 

The average human body is made of 55 to 65 percent water.

Water is the only substance on earth that is found naturally in three forms : liquids , solid and gas

Water regulates earth’s temperature 

Why do we need to drink water?

Around 60% of your body is made up of water, we need to drink it daily because it brings nutrients to cells, maintains the body’s temperature, and gets rid of wastes.

How many times a day should we drink water? 

We should drink 8 cups or 12 bottles of water, because it maintains a healthy body temperature, and avoids health problems.

Why is water important in our diet? 

Water helps in maintaining our body temperature and aids in digestion too. Aquatic animals use oxygen and nutrients present in water for their survival.