Question

Within a period the elements having the lowest electron affinity are:

• A. halogens
• B. actinides
• C. transition metals
• D. group 1A alkali metals

Answer 1

The correct option is D group 1A alkali metals

Alkali metal elements have less valence electrons(only one) in their atoms , hence they least likely will to gain electrons. Electron affinity decreases down the groups and from right to left across the periods on the periodic tablebecause the electrons are placed in a higher energy level far from the nucleus, thus a decrease from its pull.