Question

Amongst the following 3d-series elements, having highest value of first ionization enthalpy is:

Options

• Zn

• Cu

• Co

• Sc

Answer 1

Zn

Explanation:

In the 3d-series, first ionization enthalpy generally increases across the period due to an increase in effective nuclear charge. Zinc (Zn) has a completely filled 3d¹⁰ 4s² configuration, which is very stable. Hence, it requires maximum energy to remove the first electron, so Zn has the highest first ionization enthalpy among the given elements.