The correct order of increasing metallic character of $\mathrm{Na}$, $\mathrm{Be}$, $\mathrm{P}$, $\mathrm{Mg}$ and $\mathrm{Si}$ is:

Solution & Explanation

\textbf{Answer:} (A) $\text{P}<\text{Si}<\text{Be}<\text{Mg}<\text{Na}$ \textbf{Solution:} Metallic character decreases from left to right across a period and increases down a group; it varies inversely with electronegativity. Using approximate Pauling electronegativities $\text{Na }0.9<\text{Mg }1.2<\text{Be }1.5<\text{Si }1.8<\text{P }2.1$, the increasing order of metallic character (least to most metallic) is $\text{P}<\text{Si}<\text{Be}<\text{Mg}<\text{Na}$.