Question

The reason for the distinct difference in the properties of $CO_{2}$ and $SiO_{2}$ is

• A. Carbon is more electronegative than O and in case of $SiO_{2}$ oxygen is more electronegative than silicon
• B. Carbon has small size and forms a $\pi $ bond with good overlap whereas silicon has larger size hence has a poor $\pi $ -overlap
• C. First ionization potential of carbon is higher than that of silicon
• D. Carbon has only 'p' orbitals and lacks 'd' orbitals whereas silicon has 'd' orbitals

Answer 1

Answer: (B)

$CO_{2}$ is a linear discrete gaseous molecule while $SiO_{2}$ is a three-dimensional network solid as in $CO_{2}$ $\pi $ bond do not polymerised due to strong overlapping while in $SiO_{2}$ $\pi $ bond polymerised due to poor overlapping.