“A particle carrying either negative or positive charge, is called Ion.”
Types of Ions:
There are following two types of ions depending upon their nature of charge.
- The ion which has positive charge is called Cation. e.g., Na+1, Ba+2, Al+3 etc.
- A Cation is formed through removal of one or more electrons from an atom.
- Energy is required for the removal of electrons. Therefore, formation of cations is Endothermic Process.
- A Cation may carry +1, +2 or +3 charge, depending upon the number of electrons lost.
- A Cation which consists of more than one atom is called Molecular Cation. e.g., NH4+1, CH3+1 etc.
- The ion which has negative charge is called Anion. e.g., Cl-1, O-2, N-3 etc.
- An Anion is formed through addition of one or more electrons to an atom.
- Energy is released for addition of first electron, which is Therefore, Exothermic process whereas addition of second or third electrons is Endothermic Process.
- An Anion may carry -1, -2 or -3 charge, depending upon the number of electrons added.
- An Anion which consists of more than one atom is called Molecular Anion. e.g., OH-1, NO2-1 etc.