Question

what is the meaning of electron affinity

Answer 1

In chemistry and atomic physics, theelectron affinity (Eea) of an atom or molecule is defined as the amount of energy released or spent when anelectron is added to a neutral atom or molecule in the gaseous state to form a negative ion.

Answer 2

The first electron affinity is the energy released when 1 mole of gaseous atoms each acquire an electron to form 1 mole of gaseous 1- ions.

This is more easily seen in symbol terms.

It is the energy released (per mole of X) when this change happens.

First electron affinities have negative values. For example, the first electron affinity of chlorine is -349 kJ mol-1. By convention, the negative sign shows a release of energy.