Question

Rank the following elements by electron affinity, from most positive to most negative EA value.

Rank from most positive to most negative. To rank items as equivalent, overlap them

Bromine , krypton, tellurium, antimony, potassium

Answer 1

Answer :	Electron Affinity of the elements (EA) :
Tellurium	= 190.2 kJ/mol
Krypton	= 0 kJ/mol
Potassium	= 48.4 kJ/mol
Antimony	= 103.2 kJ/mol
Bromine	= 324.6 kJ/mol

Electron affinity is the measure of nuclear attraction over the newly added electron. It is the energy liberated when one electron is added to gaseous isolated atom. These values are represented with a negative sign. Greater the negative value greater is the electron affinity.

In smaller atoms, the newly added electron is attracted strongly by the nucleus and hence their electron affinity values are higher. In general, these values increase with decrease in the size.

However, in too small atoms, the new electron not only experiences the attraction from the nucleus but also the repulsions from the core electrons, which may diminish the electron affinity.

Rank of the above elements by electron affinity as follows :

Krypton, potassium, antimony, tellurium, Bromine