1.

Explain variations in atomic radii and ionisation enthalpies in group-16.

Answer»

Solution :(i) Atomic radii : The atomic radii of group-16 elements are smaller than CORRESPONDING group-15 elements. This is due to increase in effective nuclear charge.
In group-16, moving down the group, the atomic radii and IONIC radii increases due to addition of new electron shells at each successive element.
(ii) IONISATION enthalpy : The first ionisation enthalpies of group-16 elements are lower than corresponding group-15 elements. This is due to fact that group-15 elements have extra stable half-filled p-orbitals.
(iii)The ionisation enthalpy of group-16 elements are quite high due to small SIZE and high nuclear charge. However, down the group, the ionisation enthalpy decreases with the increase in atomic size.


Discussion

No Comment Found