Ion and its types

                                              Ion
  When an atom loses or gains electrons from their outermost shell ion is formed.
example:

            H  +  e-                             H-

Individual atom is a neutral specie, it has no charge because an atom has same number of electron and protons. Atom has three particles: proton, neutron, and electron. Proton and neutron is present in nucleus. Proton has positive charge and neutron has no charge.neutron is neutral particle. As a whole nucleus has positive charge due to proton. On the other hand electron has negative charge. As a whole atom has same number of protron and electrons,  means it has same number of positive and negative charges, so they cancel out each others effect so atom exist in neutral form but when an atom lose or gain electrons it gets positive or negative charge.

There are two types of ion.

1. Cation
2. Anion 

Cation

          When an atom loses electron from its outermost shell it becomes a cation. It carries a positive charge.  

cation
When atom loses electron from outermost shell it's gets positive charge because at this time: atom has greater number of protron then the electrons means atom has greater number of positive charge as compared to positive charge. When it loses 1, 2, and 3 electrons from outermost shell then it gets +1, +2, and  +3 charges respectively.

Anion

          When an atom gains electrons in its outermost shell from the other atoms then it becomes an anion. It carries a negative charge.         

    

Anion

When atom gains electron in outermost shell gets negative charge because at this time, atom has greater number of  electrons as compared to protrons means it has greater number of negative charge as compared to positive charge.When it gains 1, 2, and 3 electrons in outermost shell then it gets -1, -2, and  -3 charges respectively.