electron affinity

[205957986]

what is the trend in the periodic table of electron affinity?

[TakieraDarrow_2J]

Generally, electron affinity increases left to right. This is because, as you move from left to right across a period, the atomic size decreases, and the effective nuclear charge experienced by the electrons increases. The electron affinity tends to decrease from top to bottom. As you move down a group, the atomic size increases due to the addition of more energy levels. The outer electrons are farther from the nucleus, experiencing weaker attractive forces.

[Ashley Peterson 2C]

Hello!
To answer your question on what the trends on the periodic table are about electron affinity,
Electron affinity tends to increase across a period (left and right), and decrease down a group (top and bottom.) Within a period, the atomic size decreases and effective nuclear charge will increase, causing a stronger attraction for an additional electron and lead to a higher electron affinity. As you move down a group, the size of an atom will increase and outer electrons will move farther from the nucleus to cause a weaker attraction for an additional electron and lead to a lower electron affinity.
I believe some exceptions to the rule are elements in Group 2 (alkaline earth metals), halogens in Group 17, noble gases, and transition metals.
I hope this helps!