Question

The trend of electron affinity along a period____________

• A. Decreases
• B. Increases
• C. Constant
• D. none of these

Answer 1

Answer: (B)

Increases

Electron affinity is defined as the amount of energy released when we add an electron to the outer most shell in it's gaseous state.

In a period as the atomic size decreases as we move from left to right because of increase of nuclear charge but no change in the shell it can accept electrons easily.

In general, electron affinity increases (or becomes more negative) from left to right across a period. This is due to increasing effective nuclear charge, which more readily pulls these new electrons in.