Question

Which of the pair of elements would you expect to have lower first ionization enthalpy? Explain your answer.

Cl or S

Answer 1

S: Sulphur has a lower value of first ionization enthalpy as compared to chlorine. This is because on moving along a period from left to right the atomic size decreases and hence ionization enthalpy increases. Sulphur has a bigger size and hence lower value of its first ionization energy.