Question

Valency of carbon is?
(A) 1
(B) 4
(C) 3
(D) 2

Answer 1

Hint: Carbon is abundantly present on the earth. It forms the backbone of organic chemistry. It is found in all the living beings. It is used as fuel. The atomic number of carbon is 6.

Complete step by step answer:
Let’s look at the answer of the given question:
First we will define what is valency,
1. Valency is defined as the combining power of an element with hydrogen. The number of hydrogen which can attach to an element gives the valency of the element.
For example, the H forms 2 bonds with oxygen so the valency of oxygen is 2.
2. Now, we know that the number of electrons in the outermost shell of carbon is 4. In order to achieve the noble gas configuration of the nearest noble gas, carbon makes four bonds with hydrogen.

Therefore, the valency of carbon is 4. It is also called the tetravalency of carbon.

1. Many physical properties of carbon are explained on the basis of its tetravalency.
2. Carbon shows extensive catenation due its tetravalency and small size. Because of its tetravalency and small size carbon forms multiple strong bonds with other elements, especially hydrogen.
3. Diamond is an allotrope of carbon and it is the hardest naturally occurring substance due to the tetravalency of carbon.
Hence, the valency of carbon is 4.

So, the answer for the given question is option (B).

Note: Students can confuse valency with oxidation number. Oxidation number is the number of electrons lost or gained in a chemical reaction.
The valency of carbon in CO molecules is 3.