Question

Write the veriation of E.A in groups and periods

Answer 1

Answer:

Electron Affinity(EA) decreases gradullay down the group and increases from left to right in a period.

Explanation:

EA is energy required to add an electron to an isolated gaseous atom.

-Down the group,Size of atom goes on increasing,i.e.,distance between outermost electron and nucleus increases.So,Effective nuclear charge on outermost electron shell decreases and so it becomes easier to add electron so it decreases.

-Across period,Size of atom goes on decreasing,i.e., distance decreases so Effective nuclear charge increases and so EA needs to be increase.