Question

Which group of elements is known to have highest electron affinity?

• A. Alkali metals
• B. Noble gases
• C. Halogens
• D. Alkaline earth metals

Answer 1

Answer:

C. Halogens

• Halogens (Group 17, such as fluorine, chlorine, bromine, etc.) have a general valence shell configuration of ns² np⁵.

• They are just one electron short of achieving a stable, noble gas electron configuration, which gives them a very strong tendency to accept an extra electron.

• Consequently, they possess the highest electron affinities in the periodic table (with chlorine typically having the highest absolute electron affinity value).

• Noble gases have stable, fully filled valence shells and therefore have very low or negative electron affinities (they resist adding electrons).

• Alkali metals and alkaline earth metals tend to lose electrons (low ionization energy) rather than gain them.