Carbon has a valency of four. It is capable of bonding with four other atoms of carbon or atoms of some other monovalent element, etc. What is this property of carbon known as?
Tetravalency
A Tetravalent atom contains four atoms in its outer most shell. These electrons are available for forming covalent bonds with other atoms.
Sine, carbon has four valence electrons and can form four covalent bonds with other atoms, it is tetravalent. This property is known as Tetravalency.