Question

Which of the following is arranged in order of increasing metallic character?

• A. $P<Si<Na<Be<Mg$
• B. $Be<Mg<P<Na<Si$
• C. $Si<Be>Mg<Na<P$
• D. $P<Si<Be<Mg<Na$

Answer 1

Answer: (D)

$P<Si<Be<Mg<Na$

Metallic character depends on the two factors:

• Effective nuclear charge
• Distance from the nucleus

On moving across the period effective nuclear charge increases and the tendency to lose electrons decreases. Down the group, effective nuclear charge decreases because outermost electrons are far away from the nucleus. Therefore electrons can be lost easily.

Hence, the metallic character increases down a group from top to bottom and decreases along a period as we move from left to right. $Si$ is a metalloid and $P$ is a non-metal. Hence, the order of increasing metallic character is:$P<Si<Be<Mg<Na$.