Carbon and silicon both belong to the group 14, but inspite of the stoichiometric similarity, the dioxides, (i.e., carbon dioxide and silicon dioxide), differ in their structures. Comment.

Explanation

All members of group 14 form dioxides of formula `MO_(2)` i.e., for carbon `CO_(2)` and silica `SiO_(2).CO_(2)` has a linear structure since, its dipole moment is zero. Both the oxygen atoms are linked by double bonds. The C-atom is sp hybridised
`{:(p-p(pi),p-p(pi)),(O=C,=O),(sp-p(sigma),sp-p(sigma)):}`
However, C-O bond length is 1.15 Å, which is less than calculated value C=O bond. Hence, it shows resonance hybrid of following structures
`O=C=OharrO^(-)-C-=O^(+)harrO-=C-O^(-)`
But, the structure of silica is entirely different from that of `CO_(2).Si-O` bonds have a considerable ionic character due to large electronegative difference between Si and O. As a result, silica has a three dimensional structure in which silica atom is tetrahedrally bonded to four oxygen atoms adn each oxygen atomis bonded to two silicon atoms by covalent bonds
There is no discrete `SiO_(2)` molecule but entire crystal as a gaint molecule. Si-O bonds are strongly making it solid having high melting point.