List two characteristic features of carbon which,when put together,give rise to a large number of carbon compounds.

(N/A) The two characteristic features of carbon that lead to the formation of a vast number of carbon compounds are:
$(i)$ Catenation: The unique ability of carbon atoms to form bonds with other carbon atoms,giving rise to large molecules (chains,branched chains,or rings).
$(ii)$ Tetravalency: Carbon has a valency of $4$,which allows it to bond with four other atoms of carbon or atoms of other monovalent elements like hydrogen,oxygen,nitrogen,sulfur,chlorine,etc.