Question

Explain the trends in the following propertie, with reference to group - 16?

(a) Ionisation enthalpy.

Answer 1

These elements possess large values of ionization enthalpies which decreases gradually on moving down the group from oxygen to polonium.

This decrease is due to an increase in the size of atom and an increase in the screening effect of the electrons belonging to lower shells.

Among group-16 elements, oxygen has the highest ionization energy ($1314$ kJ mol${}^{-1}$).