Question

which group do not show regular trends in electron affinity values. ​

Answer 1

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Electron affinity decreases down the group and from right to left across the periods on the periodic table because the electrons are placed in a higher energy level far from the nucleus, thus a decrease from its pull.

Answer 2

Electron affinity decreases down the group and from right to left across the periods on the periodic table because the electrons are placed in a higher energy level far from the nucleus, thus a decrease from its pull.

Explanation: In general, elements to the right of the Periodic Table have greater electron affinity than those to their left. ... Two groups of elements (2A and 8A) have no measurable electron affinity; they do not form stable negative ions at all.