what is the valency of chlorine?

The valency of chlorine is generally 1 because a chlorine atom needs one electron to complete its outermost shell and achieve a stable electronic configuration.

Why is chlorine's valency 1?

• Atomic number of chlorine = 17

• Electronic configuration = 2, 8, 7

• It has 7 valence electrons and requires 1 more electron to complete its octet.

Example:
In sodium chloride (NaCl), chlorine gains one electron from sodium, so its valency is 1.

In simple terms: Chlorine has a valency of 1 because it needs one electron to become stable.