Question

The number of valence electrons and the variety with respect to hydrogen are.
A. Sulfur.
B. Silicon.
C. Phosphorus.
D. Chlorine.

Answer 1

Hint: We know that the electrons in the outermost shell are called valence electrons and the number of electrons it accepts or donates to form a bond is called the valency of an electron. For Example, The number of valence electrons in carbon is four and it needs four more electrons to have filled outermost electrons and hydrogen has one electron in its valence shell so carbon shares electrons with four hydrogen atoms. Thus the valency of carbon is four.

Complete answer: or Complete step by step answer: We know, Sulfur is a chemical element that belongs to the period ${\text{3}}$ and group number $6$ the period number 3 refers to the valence energy level and the group number six refers the number of valence electrons. The electronic configuration of $\left[ {Ne} \right]3{s^2}3{p^4}$ the shell $3s,3p$ is the valence energy level and the electrons in $3s,3p$ are the valence electrons and the valency of sulfur is$2$.
Therefore, option A is incorrect.
The electronic configuration is \[1{s^2}2{s^2}2{p^6}3{s^2}3{p^2}\] the outermost shell of the silicon is $3s\,3p$ thus, the number of valence electrons is four and the valency is also four.
Phosphorus is an element with atomic number ${\text{15}}$and the electronic configuration is $\left[ {Ne} \right]3{s^2}3{p^3}$ thus the number of valence electrons of phosphorus is five and the valency is three.
Therefore, option C is incorrect.
Chlorine is an element belonging to the halogens group with an atomic number $17.$ The electronic configuration is $1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6}$. Chlorine has seven valence electrons and valency is one.

So, the correct answer is “Option B”.

Note: The chemical activity of a compound or an atom depends on the number of outermost electrons. If the outermost shells are filled then the atom is inert. If the outermost shell is not filled then to fill the outermost shell, it accepts or donates electrons between other atoms.