Q. In the series to the enthalpy of atomisation of which element is least?

 1577  195 The d-and f-Block Elements Report Error

Solution:

In general, greater the number of unpaired electrons, greater is the number of bond and therefore, greater is the strength of these bonds, thus higher will be enthalpy of atomization.

Enthalpy of atomization first increases in a series (as unpaired electrons increases from 1 to 6 ), reaches to maxima and then decreases, and it is lowest for (due to 0 unpaired electrons).