JEE Chemistry 2023 Question with Solution

Given: The order of metallic character is to be compared for $Si$, $Be$, $Mg$, and $K$.

Find: The correct increasing order of metallic character.

Metallic character refers to the ability of an element to lose electrons and form positive ions. As we move down a group in the periodic table, the atomic size increases, and the outer electrons are farther from the nucleus, making it easier for the element to lose electrons. Therefore, metallic character increases down a group.

As we move from left to right across a period, the atomic size decreases and the effective nuclear charge increases, making it harder for an element to lose electrons. Therefore, metallic character decreases across a period from left to right.

Among the given elements, $K$ is an alkali metal in Group $1$, so it has the highest metallic character. $Si$ is a metalloid in Group $14$, so it has the least metallic character among the given elements. Between $Be$ and $Mg$, metallic character increases down the group, so $Mg > Be$.

Hence, the correct order is

Therefore, the correct option is A.

The solution displays D as the correct option label, but its written sequence concludes $Si < Be < Mg < K$, which matches option A. Therefore, the sequence in the explanation is taken as authoritative.

Given: Metallic character depends on the tendency to lose electrons.

Find: Which arrangement shows increasing metallic character.

Use periodic trends:

1. Down a group, metallic character increases.
2. Across a period from left to right, metallic character decreases.

Applying this:

• $K$ is most metallic.
• $Si$ is least metallic.
• Between $Be$ and $Mg$, $Mg$ is more metallic because it lies below $Be$ in the same group.

So the increasing order becomes

Thus, the correct option is A.