If a gas  expands  at constant  temperature,  it indicates that

A compound formed  by elements A and B crystallises in the cubic structure, where  A  atoms are present  at the  corner of a  cube and B atoms  are present at the  face centres.  The formula  of the compound is

A  pure  crystalline substance  on being  heated  gradually  first forms a  turbid  liquid at constant  temperature and still at  higher  temperature turbidity completely disappears. The  behaviour is a characteristic of substance forming

With which one of the following  elements  silicon should be doped so as to give p- type  of semiconductor?

When is the  deviation  is more in  the behaviour  of a gas  from the  ideal gas  equation pV= nRT?

The appearance  of colour  in solid  alkali metal halides is  generally  due to

When electrons are trapped into the  crystalline anion  vacancy,  the defect  is known as

Which one of the  following  is wrong statement  for gases?

Most  crystals  show  good cleavage  because  their atoms, ions or  molecules  are

Cyclopropane and oxygen at  partial pressures  170 Torr and 570 Torr are  mixed  in a   gas  cylinder.  What is the ratio of the  number of moles  of cyclopropane to the number  of moles of oxygen?