${\mathrm{PbCl}}_4$ is less stable than ${\mathrm{PbCl}}_2$.

Give the formula of a compound in which carbon exhibit an oxidation state of $+4$.

Give the formula of a compound in which carbon exhibit an oxidation state of $+2$

Give the formula of a compound in which carbon exhibit an oxidation state of $-4$.

Explain the trend of atomic radii in group $13$ elements.

Explain the trend of ionisation enthalpy in group $13$ elements.

Explain the trend of electron affinity in group $13$ elements.

Name a molecule having banana bond.

Draw the resonance structure of nitric acid.