Schottky defect defines imperfection in the lattice structure of a

Identify the defect that develops when the ratio of number of cations to anions becomes different from that indicated by its chemical formula.

The color of metal ions in flame is due to which of the following?

If an electron is present in place of an anion in a crystal lattice,then it is called

State the types of point defects.

The formula of nickel oxide with metal deficiency defect in its crystal is $Ni_{0.98}O$. The crystal contains $Ni^{2+}$ and $Ni^{3+}$ ions. The fraction of nickel existing as $Ni^{2+}$ ions in the crystal is