Question

The first ionization energy of magnesium is smaller as compared to that of elements $X$ and $Y$, but higher than that of $Z.$ The elements $X,Y$ and $Z$ , respectively, are

• A. chlorine, lithium and sodium
• B. argon, lithium and sodium
• C. argon, chlorine and sodium
• D. neon, sodium and chlorine

Answer 1

The correct option is C argon, chlorine and sodium

Considering the third period elements, first ionisation energy of $Mg$ is smaller than Argon and chlorine but will be higher than $Na.$

So $X\to \text{Argon}$
$Y\to \text{Chlorine}$
$Z\to \text{Sodium}$
Option C is the correct answer