D And F Block Elements

CrO is basic but $\mathrm{Cr}_2 \mathrm{O}_3$ is amphoteric.

Nitrite is oxidised to nitrate in acidic medium by $\mathrm{KMnO}_4$.

$\mathrm{PdCl}_2$ is the catalyst in Wacker process.

The reactivity of the earlier members of lanthanide series is similar to that of aluminium.