Which of the following represents the correct order of increasing first ionization enthalpy for Ca, Ba, S , Se and Ar ?

Options

A. `Ca lt Ba lt S lt Se lt Ar`
B. `Ca lt S lt Ba lt Se lt Ar`
C. `S lt Se lt Ca lt Ba lt Ar`
D. `Ba lt Ca lt Se lt S lt Ar `

Answer

D

Explanation

In general, ionization enthalpy decreases from top to bottom `(Ba lt Se), (Se lt Ar).` Therefore, correct order of increasing first ionization enthalpy is :
`Ba lt Ca lt Se lt S lt Ar`