Select correct statement(s) about non-stoichiometric compounds 

Options

A. They are called Berthollide compounds
B. They do not obey the law of constant composition
C. Electrical neutrality is maintained either by having extra electrons in the structure or changing the charge on some of the metal ions
D. no effect on density of crystal due to these defects

Answer

A, B, C

Explanation

Non-stoichometric compounds are called Berthollide because they do not obey the law of constant composition. Electrical conductivity is maintained either by having extra electrons in the structure (or) changing the charge on some the metal ions