Question

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

Answer 1

But due to its higher atomic number (in comparison to Carbon), its atoms aretoo large to fit together into as great avariety of molecules as carbon atoms can. ... Hence carbon as an element has the ability to form a variety of stable compounds, which can existfreely in nature.

Answer 2

Existence of Large number of Carbon Compounds is due to its Self-Linking Property (Catenation). Carbon is a small atom with Atomic number 6 has 4 valence electrons.

Generally if a compound accepts more number of electrons there will be repulsions from inner-shells due to which the compounds become unstable. But Carbon is a special Compound where only 2 electrons are present in its inner Shell due to which repulsions will be very less. Hence Carbon has very less repulsive forces due to which it is able to form large number of compounds.

Even The same group compounds like silicon also forms many compounds like silicates, silicones etc.. But not as many as carbon compounds, because it has more number of inner relative to carbon.