Question

Elements with valency $1$ are:

• A. Always metals
• B. Always metalloids
• C. Either metals or non-metals
• D. Always non-metals

Answer 1

The correct option is C

Either metals or non-metals

Explanation for correct option:

Option C: Either metals or non-metals:

1. The number of electrons gained or lost by an atom in order to complete eight electrons in its valence shell is known as its valency.
2. For metal - Sodium: The number of valence electrons is $1$. Thus, the valency of sodium is $1$.
3. For non-metal - Chlorine: The number of valence electrons is $1$. Thus, the valency of chlorine is $1$.

Thus, elements with valency $1$ are either metals or non-metals.

Explanation for incorrect options:

Option A: Always metals:

Non-metals can also have valency $1$.

Option B: Always metalloids:

Metals and non-metals both can have valency $1$.

Option D: Always non-metals:

Metals can also have valency $1$.

The correct option is Option C.