Chemistry

Problem

The first I.E. of Na, Mg, Al and Si are in the order : a.

\text{Na} < \text{Mg} < \text{Al} < \text{Si}

\text{Na} < \text{Al} < \text{Mg} < \text{Si}

\text{Na} < \text{Al} < \text{Si} < \text{Mg}

\text{Na} > \text{Mg} > \text{Al} > \text{Si}