Question

How does nuclear charge affect the electron affinity?

Answer 1

Electron affinity

1. Electron affinity (EA) or also known as Electron Gain Enthalpy is the amount of energy released by the addition of an electron to the outermost shell of an atom in its isolated gaseous state.
2. Its SI unit is $\mathbf{kJ}\mathbf{/}\mathbf{mol}$.

$\mathbf{\chi }\mathbf{\left(}\mathbf{g}\mathbf{\right)}\mathbf{}\mathbf{+}\mathbf{}{\mathbf{e}}^{\mathbf{-}}\mathbf{}\mathbf{\to }\mathbf{}{\mathbf{\chi }}^{\mathbf{-}}\mathbf{\left(}\mathbf{g}\mathbf{\right)}\mathbf{}\mathbf{+}\mathbf{}\mathbf{EA}$

$\mathbf{\chi }$ is any element taken in its gaseous state.

Effect of nuclear charge on electron affinity

1. Greater the nuclear charge, the greater is the electron affinity.
2. This is because the increase in nuclear charge increases the effective attractive force on the valence electrons.