Question

Which is the characteristics flame colouration of Li?

• A. Yellow
• B. Blue
• C. Violet
• D. Crimson red

Answer 1

The correct option is D Crimson red

The alkali metals and their salts impart a characteristic colour to flame. On heating an alkali metal or its salt (especially chlorides due to its more volatile nature in a flame), the electrons are excited easily to higher energy levels because of absorption of energy. When these electrons return to their ground states, they emit extra energy in form of radiations which fall in the visible region thereby imparting a characteristic colour to the flame. Lithium salts exhibit crimson red colour at wavelength 680.7 nm.