Question

what is the overall trend for the electron affinity of atoms across the groups and periods? electron affinity increases down the groups and decreases from left to right across the periods. electron affinity increases down the groups and increases from left to right across the periods. electron affinity decreases down the groups and increases from left to right across the periods. electron affinity decreases down the groups and decreases from left to right across the periods.

Explanation:

As the atomic size increases down a group, the added electron is farther from the nucleus, resulting in a decrease in electron - affinity. Across a period from left to right, the effective nuclear charge increases, and the atomic size decreases, making it easier to add an electron, thus increasing electron - affinity.

Answer:

Electron affinity decreases down the groups and increases from left to right across the periods.