Chemistry

Problem

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

\text{Ba} < \text{Ca} < \text{Se} < \text{S} < \text{Ar}

\text{Ca} < \text{Ba} < \text{S} < \text{Se} < \text{Ar}

\text{Ca} < \text{S} < \text{Ba} < \text{Se} < \text{Ar}

\text{S} < \text{Se} < \text{Ca} < \text{Ba} < \text{Ar}