What causes the existence of very large number of carbon compounds?

Explanation

(i) Carbon is the only element that can form so mang different compounds because each carbon atom can form four chemical bonds with other atoms.
(ii) Having the atomic number 6, every carbon atom has a total of six electrons. The carbon atom's fou valence electrons can be shared by other atom forming covalent bonds, gives them the abilit to form long carbon - to - carbon chain, the can even join "head - to - tail" to make rings a carbon atoms.
(iii) Carbon atoms can share not only a single electror with another atom to form a single bond, but it can also share two or three electrons, forming double or triple bond.
(iv) This makes a huge number of different possible 'molecules. Hence, carbon forms large number a compounds, because of all these properties.