Question

Elements with valency 1 are

• A. always metal
• B. always metalloids
• C. either metal or non-metal
• D. always non-metal

Answer 1

The correct option is C

either metal or non-metal

The correct option is (C).

Explanation of the correct option:

1. The number of electrons present in the outermost shell(valence shell) of an atom tells the valency of an element.
2. Valency is the number of electrons gained or lose from its outermost shell(valence shell) in order to complete its octet and have a stable electronic configuration.
3. Elements with valency 1 mean that they can either gain an electron or it can lose one electron.
   (i) If it gains one electron then it acquires a negative charge(-1) and becomes a non-metal.
   (ii) If it loses one electron then it acquires a positive charge(+1) and becomes a metal.
4. Hence elements with valency 1 can either be metal or non-metal depending upon whether they lose or gain electrons to become stable.

Explanation of the incorrect option:

Option (A):

Elements with valency 1 cannot be always metal since they can also gain one electron and can become non-metal.

Option (B):

Metalloids are the elements that resemble the properties of both metals and non-metals. Thus elements with valency 1 cannot be metalloids.

Option (D):

Elements with valency 1 cannot be always non-metal since they can also lose one electron and can become metal.

Hence, Elements with valency 1 are either metal or non-metal.