What are the two properties of carbon which lead to the huge number of carbon compounds we see around us

What are the two properties of carbon which lead to the huge number of carbon compounds we see around us?

Answer: Two properties of carbon that attributes to its large family of carbon compounds are:

1. Catenation: Ability to form chains with other atoms of carbon by covalent bonding.
2. Tetravalency: Valency = 4 i.e. it forms four covalent bonds with four other atoms.