Question

The $I{E}_1$ of $Na,Mg$ and $Si$ are $496,737$ and $786$ kJ $mo{l}^{-1}$ respectively. The expected $I{E}_1$ of $Al$ would be between:

• A. $496-737$
• B. $737-786$
• C. more than $786$
• D. less than $496$

Answer 1

The correct option is A $496-737$

Since$,$ $Mg$ has completely filled configuration than $Al,$

Hence $IE=Na>Al$

or $IE=Na<Al<Mg<Si,$

Moving through period from left to right$,$ $IE$ increases due to less size of atoms$.$