Fill in the following blanks with suitable words:

(a) The particle which is formed by the gain of electrons by an atom is called ………….

(b) The particle which is formed by the loss of electrons by an atom is called ………….

(c) The particle which is formed by the loss or gain of electrons by an atom is called ……….

(d) A potassium ion has positive change because it contains less …………. than ………….

(e) A sulphide ion has negative charge because it contains less …………… than ……………