`AlF_3` is a high melting solid whereas `SiF_4` is a gas. Explain.

AIF _3' is a high melting solid whereas 'SiF_4' is a gas. Explain why??

Give reasons for the following: CO_2 is a gas whereas SiO_2 is a solid.

A particular solid is very hard and has very high melting point. In solid state, it is a non - C0nductor and its melt is a C0nductor of electricity. Classify the solid

Alkali metal halides are all high melting, colourless crystalline solids. How alkali metal halides are prepared?

Alkali metal halides are all high melting, colourless crystalline solids.Write any other physical property of alkalimetal halides.

Explain why (a) '(Ce4+' is a good oxidistng agent whereas '(Sm2+ is a good reducing agent b) '(La)(OH)_(3)' is stronger base than '(Lu)(OH)_(3)'

[Cr(NH3)6]^3+ is paramagnetic while [Ni(CN)4]^2- is' diamagnetic. Explain why?

Solid A is very hard, insulator in solid as well as in molten state and melts at extremely high temperature. What type of solid is it?