Question

The ionization potential of elements in any group decreases from top to bottom. This is due to :

• A. increase in the size of an atom
• B. increase in the atomic number
• C. increase in the screening effect
• D. both increase in the size of an atom and increase in the screening effect

Answer 1

Answer: (D)

both increase in the size of an atom and increase in the screening effect

The ionization potential of elements in any group decreases from top to bottom.
This is due to both increase in the size of an atom and increase in the screening effect.
Due to this, the effective nuclear charge decreases. The attraction of the nucleus for the valence electrons decreases.
This decreases the ionization potential.