Thursday, June 13, 2013

Atomic number

We already know that atoms are super small things,
and that they have even smaller protons, neutrons and electrons in them.

We also know that chemical elements and molecules make up all the things in the world,
from the air to the water to the earth.

Each one of those chemical elements is different, because of the number of protons it has.

And the number of protons an atom or element has, we call that the atomic number.
It's different for every chemical element in the world!
atomic number
(from: wikipedia - atomic number)

For example, oxygen has 8 protons, and gold has 79.