All the trihalides exist except $\mathrm{TII}_3$.

Trihalides on hydrolysis form tetrahedral species.

Diborane is an example of electron precise hydride.

Hydrolysis of diborane gives boric acid.

In addition to $+4,+2$ carbon also shows negative oxidation states.

Tin in +2 state acts as a reducing agent.

Lead in +2 state acts as good reducing agent.

Lead in +4 state acts as a good oxidising agent.

I and II only

II and IV only

I, III and IV only

I, II and IV only

Chlorine oxidises ferrous salts to ferric salts in acidic medium.

Chlorine oxidises iodine to periodic acid in water.

Chlorine acts as a bleaching agent due to oxidation.

Chlorine is manufactured by Deacon's process.