Question

What is the valency of carbon?

(a) Pentavalent

(b) Divalent

(c) Trivalent

(d) Tetravalent

This question was addressed to me in a national level competition.

The query is from Tetravalence of Carbon: Shapes of Organic Compounds topic in division Organic Chemistry – Basic Principles and Technique of Chemistry – Class 11

Answer 1

Right choice is (d) Tetravalent

The explanation is: The atomic number of carbon is 6 and thus it has 4 valence electrons. So, it can either accept 4 electrons or donate 4 electrons in order to become stable. But it is difficult for carbon to neither lose 4 electrons due to its strong force of attraction with the nucleus nor gain 4 electrons since the protons in the nucleus are not sufficient to hold 8 electrons in them. Therefore, carbon forms 4 covalent bonds with other atoms, thereby, exhibiting tetravalency.