the-electron-affinity-increases-as-you-go-up-a-group-as-an-example-se-has-a-high

Question

The electron affinity increases as you go up a group. As an example, S has a higher electron affinity than Se. However, O which is above S has a lower electron affinity than S.

What is the reason for this phenomenon?

Accepted Answer

O having a much smaller radius causes the electron affinity to be less exothermic because of the repulsive forces between the electrons

Answer

O having much fewer protons causes the electron affinity to be less exothermic because of the repulsive forces between the protons

Answer

O having a much smaller nucleus causes the electron affinity to be less endothermic because of the attractive forces between the electrons

Answer

O having much fewer electrons causes the electron affinity to be less endothermic because of the attractive forces between the electrons

My Courses

Chemistry

Biology

Math

Physics

Business

Social Sciences

Programming

Product & Marketing

The electron affinity increases as you go up a group. As an example, S has a higher electron affinity than Se. However, O which is above S has a lower electron affinity than S.
What is the reason for this phenomenon?