Lab & calculation
Flame test — শিখা পরীক্ষা
Quick answer
Identifying metal ions by flame colour: Na golden yellow, K lilac, Ca brick red, Cu green — electrons falling back emit light.
Definition
A flame test identifies certain metal ions by the colour their electrons paint into a hot flame. Heat excites the metal atoms; their electrons jump to higher shells and fall back, releasing the extra energy as visible light of a signature colour. Sodium glows golden yellow, potassium lilac, calcium brick red, and copper green. The test is quick but qualitative: it flags which ions may be present, and chemists confirm with more precise instruments.
For example
Touch a clean wire with a pinch of table salt to a blue burner flame and it flares golden yellow — sodium's signature, a school lab classic.