Question

electroaffinity increase across a peroid why

Answer 1

because non metallic character inc.

Answer 2

This is very easy to understand.
Electron affinity is the tendency of elements to get attracted towards electron.
As we know that non metals are electronegative and accept electrons.
As well as we move towards the left of periodic table across a period, the tendency to gain electron increases due to
•High charge of nucleus
•tendency to gain electrons