Chemistry - Solid State Question with Solution | TestHub

Intrinsic defects are those that arise naturally in a crystal structure without the addition of foreign atoms. Frenkel defects and Schottky defects are common types of intrinsic point defects. Metal deficiency defects are also intrinsic as they occur due to non-stoichiometry within the compound itself. Impurity defects, however, are extrinsic, caused by the presence of foreign atoms.

Therefore, the correct options are A, B, and D.