$-3,+1$

$+1,-3$

$0,-3$

$+1,+2$

Aluminium dissolves in conc. $\mathrm{HNO}_3$ and liberates $\mathrm{H}_2$ gas

Borazole contains $12 \sigma$ and $3 \pi$ bonds

Gallium oxide is amphoteric in nature

$\mathrm{BF}_3$ is a Lewis acid

30

31

32

33

Potassium permanganate on heating gives potassium manganate and manganese dioxide only

Phosphine is used in smoke screens

Bleaching action of chlorine is due to oxidation

Noble gases have very low boiling points