Question

Element P has atomic number 19. To which group does P belong?
(A) 1
(B) 2
(C) 17
(D) 16

Answer 1

Hint: to solve this question refer to the electronic configuration of the given element as the atomic number has been given to us. As we can find the group number by the number of valence electrons.

Complete step by step answer:
We have been provided with an element P whose atomic number is 19,
So, as we need to find the group to which P belongs to,
So, for that:
Firstly, we will be finding the electronic configuration of the element P,
As we have been given the atomic number of the element P which is equal to 19,
so, the electronic configuration would be:
\[P=1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{2}}3{{p}^{6}}4{{s}^ {1}} \]
So, for atomic number 19, the valence shell would be equal to 4,
And we know that the period number corresponds to the number of valence shell occupied by the element,
So, the period to which the element P belongs is 4,
Now, for atomic number 19, the number of valence electron is 1 in the s subshell,
And we are aware that the group number corresponds to the number of valence electrons of that element,
So, the group to which the element P belongs is 1.
So, from this we can conclude that element P belongs to group 1.

Therefore, the correct option (A).

Note: As the element P belongs to group 1 or we can say that it has 1 valence electrons, so it can denote 1 electron and hence it is a metal, as metal has the tendency to lose or donate electrons.