The metal ions impart colour of the flame due to:

Options

A. Frenkel defect
B. Metal excess defect
C. metal deficiency defect
D. Schottky defect

Answer

B

Explanation

Metal excess defect
Explanation: The flame colours of metal ions are due to metal excess defect. These type of crystals are generally coloured. This is due to presence of free electrons. These electrons get excited easily to higher energy levels by absorption of certain wavelengths from the visible light and therefore, the compounds appear coloured.