Question

Which of the following remains unchanged on going down the group in the periodic table?

• A. Valence electrons
• B. Atomic size
• C. Density
• D. Metallic character

Answer 1

The correct option is A

Valence electrons

Explanation for correct option:

(A) Valence electrons

• The valency of an element can be identified by the valence electrons of an atom.
• Elements belonging to the same group have the same number of valence electrons and thus, will have the same valency.
• For example, Group$-\left(1\right)$ elements have one valence electron in their outermost shell.
• Valence electrons remain unchanged along a specific group in the periodic table.

Hence, the correct option is (A).

Explanation for the incorrect options:

(B) Atomic size:

• The Atomic size increases on moving down the group.

(C) Density:

• Density increases down the group in the periodic table.

(D) Metallic character:

• Metallic character increases on moving down the group.

Therefore, option (A) Valence electrons is correct. Valence electrons remain unchanged on going down the group in the periodic table.