• # question_answer The first ionization potential of Na, Mg, Al and Si are in the order A) $Na<Mg>Al<Si$             B) $Na>Mg>Al>Si$ C) $Na<Mg<Al>Si$             D) $Na>Mg>Al<Si$

Ionisation energy increases from left to right in a period. However, exception occur between group - 2 and group -13 elements on account of stability of electronic configuration of valence shell. $\Rightarrow$The desired order is : $Na<Mg>Al<Sl$