Question

The atoms of elements belonging to same group of the periodic table have same number of

• A. Protons
• B. Electrons
• C. Neutrons
• D. Electrons in the outermost shell

Answer 1

The correct option is D

Electrons in the outermost shell

Explanation for correct option:

(D) Electrons in the outermost shell

• The elements belonging to the same group of the periodic table have the same number of electrons in the outermost shell.
• For Example: Consider elements present in Group-1 i.e. $\mathrm{Li}$ and $\mathrm{Na}$. Lithium has the atomic number $3$, while atomic number for sodium is $11$.

Electronic configuration of $\mathrm{Li}$ :$1{\mathrm{s}}^{2}2{\mathrm{s}}^1$

Electronic configuration of $\mathrm{Na}$ :$1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^1$

The electron in the outermost shell for both the elements is $1$.

Explanation for incorrect options:

(A) The atoms of elements belonging to the same group of the periodic table will not have same protons since the atomic number is different.

(B) The atoms of elements belonging to the same group of the periodic table will not have same electrons since the atomic number is different.

(C) The atoms of elements belonging to the same group of the periodic table will not have same neutrons since the atomic number is different.

Therefore, option (D) is correct. Elements belonging to the same group will have same electrons in the outermost shell.