Question
Why do alkali metals impart colour to the flame?
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Answer
Alkali metals are largest in size in their respective periods and hence, have low ionisation enthalpies. Their valence electrons easily absorb energy levels. When thesa electron return to the ground state, the absorbed energy is emitted, which falls in the visible region imparting colour to the flame e.g., lithium imparts crimson red, sodium imparts golden yellow.
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