Question

explain the trend in following atomic properties of group 16 elements​

Answer 1

Atomic and Ionic radii: The atomic and ionic radii increase as we go down the group-16 from oxygen to polonium. This is due to the addition of new shell and decrease in effective nuclear charge at each successive element on moving down the group.

Across the period, i.e., on moving from group 15 to group 16 in a period, the effective nuclear charge increases. Therefore, the electrons in the outer shell of group 16 elements experience a greater nuclear pull which results in a decrease in the atomic and ionic radii.