Question

Which of the following had maximum valence electrons? (Atomic numbers are given in brackets)

• A. $\mathrm{Na}\left(11\right)$
• B. $\mathrm{N}\left(7\right)$
• C. $\mathrm{Mg}\left(12\right)$
• D. $\mathrm{Si}\left(14\right)$

Answer 1

The correct option is B

$\mathrm{N}\left(7\right)$

The correct option is (B).

Explanation of Correct Option:

1. A number of electrons present in the outermost shell of an atom is called valence electrons.
2. Atomic number. of Nitrogen $\left(\mathrm{N}\right)$ is $7$ and has the electronic configuration as $(2,5)$.
3. From the electronic configuration of the nitrogen atom, we come to know that the number of electrons present in the outermost shell i.e., 2nd shell is 5 electrons.
4. Thus, the total number of valence electrons present in nitrogen atoms is five.

Explanation of Incorrect Options:

Option (A): $\mathrm{Na}\left(11\right)$

Atomic number of Sodium $\left(\mathrm{Na}\right)$ is $11$and has it's electronic configuration as $(2,8,1)$. Thus, the total number of valence electrons present in Sodium atoms is one.

Option (C): $\mathrm{Mg}\left(12\right)$

Atomic number of Magnesium $\left(\mathrm{Mg}\right)$ is $12$ and has it's electronic configuration as $(2,8,2)$. Thus, the total number of valence electrons present in Magnesium atoms is two.

Option (D): $\mathrm{Si}\left(14\right)$

Atomic number of Silicon $\left(\mathrm{Si}\right)$ is $14$ and has it's electronic configuration as $(2,8,4)$. Thus, the total number of valence electrons present in Silicon atoms is four.

Hence, option (B) Nitrogen$\left(\mathrm{N}\right)$ has the maximum number of valence electrons.