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the electron affinity of atoms is also periodic. The electron affinity of an ato

ID: 926735 • Letter: T

Question

the electron affinity of atoms is also periodic. The electron affinity of an atom is the energy that is lost or gained when an electron is added to a neutral atom of the element in a gaseous state. A more negative electron affinity is considered a higher electron affinity value. It tends to become more negative going from left to right across a row in the table and less negative going down a column. Electron affinities are not as smoothly periodic as some of the other properties, with some major exceptions opposing the general trends. For example, the group 2 and group 18 elements have positive electron affinities, and each of the row 2 elements B through F are less negative than the elements just below them in the column. In general, however, electron affinities tend to be more negative as you move toward the upper right-hand corner of the periodic table.

Which element has the highest (most negative) electron affinity?

Xe

F

Cs

Be

Co

Explanation / Answer

from the given elements

Cs and Be are situated at the extreme left of the perioidc table

Co is in the middle of the periodic table

Xe and F are the extreme right of the perioidc table

we know that

electron affinity increases across a row

so

elements at the extreme right of the periodic table have highest electroon affinity

so

one of Xe and F should have highest electron affiniity

so

consider Xe and F


Now

electron affinity decreases as we go along the column

also

Xe is a noble gas ,

so it should have very less electron affinity

SO


F should have the highest electron affinity

So

the answer is F