Total number of TRUE statements about silicones/silicates?
i. Silicones resist oxidation and attack by organic reagents.
ii. Silicones are lubricants at low as well as high temperature.
iii. Cross-linked silicones are formed by the hydrolysis of tricholorosilicone $\left({\mathrm{RSiCl}}_3\right)$ and subsequent polymerization.
iv. Both silicones and silicates(polymeric form) compound contains $\mathrm{Si}-\mathrm{O}-\mathrm{Si}$ linkage.
v. Silicones are good electrical insulator and are antifoaming agents.