Question

Among the elements B Al, C and Si,
(i) Whlich element has the highest first ionisation enthalpy?

(ii) Which element has the mjost metallic cahracter? Justify your answer in each case.

Answer 1

(i) The placing of elements are as

Ionisation enthalpy increases along a period (as we move from left to right in a period) with decreases in atomic size and decreases down the group with the increase in atomic size. Hence, carbon has the highest first ionisation enthalpy.

(ii) Metallic character decrease across a period but increases on moving down the group. Hence, aluminium has the most metallic character.