Question

Electron affinities of C,Si and Ge follow the order

Answer 1

electron affinities of C,Si,Ge follow the order
$c < si > ge$

Answer 2

Explanation:

When an electron is added to a neutral atom it results in the formation of a gaseous negatively charged ion. The energy released during this process is known as electron affinity.

For example, $Cl + e^{-} \rightarrow Cl^{-}$ + Electron affinity

Electron affinity decreases down the group because the size of atom increases and the added electron releases less amount of energy. As a result, there will be decrease in electron affinity.

But, out of carbon and silicon, the electron affinity of silicon is greater than carbon because silicon has empty 3d orbital. So it can accommodate added electrons into the empty 3d orbital whereas carbon does not have any empty orbital so added electron will feel high repulsive forces.

Thus, electron affinity of carbon will decrease.

Hence, the electron affinitiy order is as follows.

                               C < Si > Ge