C2 - Atoms (1)
Nucleus contains protons and neutrons.
Nucleus has a positive charge because of protons (+1)
Electrons are negatively charger.
NUMBER OF PROTONS = NUMBER OF NEUTRONS
* If some electrons are added or removed the atom becomes charged and is then an ion *
Number above element is MASS NUMBER.
Number below element is ATOMIC NUMBER.
Neutrons = Mass number - atomic number