Question

By moving top to bottom in group, valency will

• A. increase
• B. decrease
• C. No change
• D. increase and decrease

Answer 1

The Correct Option is C

Valency is defined as the ability of an atom to combine with other atoms when forming chemical compounds or molecules. It is often determined by the number of electrons in an atom's outermost shell, which is known as the valence shell. When you move down a group in the periodic table, the elements have the same number of electrons in their outermost shell. 

Therefore, the valency of elements in a group remains constant as you move from top to bottom. 
For example, in Group 1 (Alkali metals), all elements have 1 electron in their outermost shell, leading to a consistent valency of 1. 

Hence, the correct answer is: No change

Answer 2

Correct answer: No change 

Explanation:
As we move from top to bottom in a group of the periodic table, the number of valence electrons remains the same. Hence, the valency of elements in the same group does not change.

Valency remains constant down a group.