Question

VALENCY
The number of hydrogen atoms which can combine with or displace -
one atom of the element or radical so as to form a compound.

Q)I haven't understood why the word 'displaced' is used in this definition?

Please explain thoroughly ​

Answer 1

Answer:

Valency is the number of hydrogen atoms that can combine with [or displace] one atom of the element (or radical) to form a compound. For example, one atom of hydrogen combines with one atom of chlorine to form hydrogen chloride (HCl); so, the valency of chlorine (chloride) is one.

Explanation:

Answer 2

Answer:

Valency is the number of hydrogen atoms that can combine with [or displace] one atom of the element [or radical] to form a compound. For example, one atom of hydrogen combines with one atom of chlorine to form hydrogen chloride [HCl]; so, the valency of chlorine [chloride] is one.