Question

Catenation is the ability of an atom to form bonds with other atoms of the same element. It is exhibited by both carbon and silicon. Compare the ability of catenation of the two elements. Give reasons.

Answer 1

Hint:To answer this question, you must recall the concept of catenation. Catenation can be defined as the joining of atoms of the same element forming a long chain. To compare the extent of catenation in carbon and silicon, we will have to apply the concept of bond energies of carbon- carbon covalent bond and silicon direct bonding.

Complete answer:
Catenation is the property of an element that enables it to form covalent bonds within the atoms of the same element forming a long chain or ring of atoms. The ability of catenation depends on electronic and steric factors of an atom, namely the electronegativity of the element, the ability to form different types of double bonds and the arrangement of the molecular orbitals of the element around it.
Carbon has the ability to catenate most readily and can form very long carbon- carbon chains. Whereas, catenation in silicon is not as extensive as in carbon because the strength of Silicon- silicon bond is not as strong as compared to the carbon- carbon bond. This is due to the greater size of the silicon atom and hence the silicon- silicon overlapping is not very effective.

Note:
The bond formed between two carbon atoms is a covalent bond. Most commonly a single bond is formed which composes of one electron from each carbon atom. Carbon- carbon single bond is known as a sigma bond formed using one hybridized orbital of each of the two carbon atoms.
The silicon direct bonds are formed on the basis of intermolecular attractions like hydrogen bonding, Van der Waals forces and strong covalent bonds.