Tuesday, January 31, 2012

What’s the matter?

Matter is anything that occupies space and has weight. It means everything!

Is air a matter? Yes it is, though you don’t see it but it occupies space and it has molecular mass of 29 g/mol. The air we breathe is composed of 21% Oxygen, 78% Nitrogen and 1% other gases.

Basically there are three states of matter and they are solid, liquid and gas. The other two are quite complex to understand and cannot occur in normal conditions, Plasma is the fourth one and Bose-Einstein condensate as the fifth state.

So let’s focus on Solid, Liquid and Gaseous states.

Solid has definite shape and volume. Examples are stone and steel.

Liquid has a definite volume but takes the shape of the container. Examples are water and oil.

Gas has neither definite volume nor a definite shape. Examples are oxygen and helium.

Some matters can exist not only on one state, a perfect example is water. Water is naturally in liquid state but once it is subjected to an increase in temperature can be converted to water vapor or when subjected to a decrease in temperature turn into ice.

Addition of Energy changes state
from Chem4Kids

The change from one state to another, in water's case from ice to liquid, then from liquid to gas are called physical changes because it only changes the appearance but the composition will still be of water or H2O.