Question

Describe the trend of ionization potential down the group in the periodic table.

Answer 1

Ionization energy:

• It is the minimum amount of energy required to remove the outermost electron from an isolated neutral gaseous atom of that element in its lowest energy state to form a positive ion (cation).
• This energy is called the first ionization energy/potential.

Ionization potential:

• The minimum amount of energy required to remove the electron from a gaseous atom is called its ionization potential. The second ionization potential is the energy required to remove the electron from the outermost shell of a unipositive charged gaseous ion.
• Variation of ionization potential down the group:
• The ionization potential decreases from top to bottom in a group as the atomic size increases down the group, thus resulting in the decrement of the nuclear force of attraction towards the electron to be removed.

The ionization potential decrease down the group in the periodic table.