(i) Silicon are the group of organosilicon polymers having (R₂SiO) repeating unit. For manufacturing silicone, starting material is alkyl or aryl substituted silicon chloride.

Methyl chloride react with silicon in the presence of copper powder as a catalyst at 573K, many types of methyl chlorosilanes like MeSiCl₃, Me₂SiCl₂, Me₃SiCl with small amount of Me₄Si are formed. Further addition of water form the straight-chain polymer.

Uses:

They are used as greases, sealant, for waterproofing fabric, electrical insulators.

Also used as a surgical and cosmetic plant.

(ii) Borane is a simple form of boron hydride. It is prepared by treating lithium aluminium hydride with trifluoride in diethyl ether.

4BF₃ + 3 LiAlH₄ → 2B₂H₆ + 3LIF + 3AlF₃

It is also prepared by oxidation of sodium borohydride with iodine. For example:

2NaBH₄ + I₂ → B₂H₆ + 2NaI + H₂

Diborane is also produced on an industrial scale by reacting with BF₃ with NaH

2BF₃ + 6NaH → B₂H₆ + 6NaF

Diborane is colourless gas and is highly toxic. It has boiling point 180K.