Atomic Structure

The atom is made up by three sub-atomic particles Electrons, Protons and Neutrons.



Protons are particles located in the atomic nucleus. They each have a positive charge. The number of protons of each element is equal to the atomic number

Electrons are tiny negative particles that are found around the nucleus. The number of electrons in a neutral atom is equal to the atomic number.

Neutrons are particles with a similar mass as protons also found in the nucleus. They have a neutral charge. The number of neutrons can be found by subtracting the atomic number from the atomic mass.

Isotopes
The atomic mass on the periodic table is actually an average of the actual atomic masses. This means the different variations of each element exists. For instance there are O-15, O-16 and O-17, however O-16 is the most common therefore we use O-16 as the average.