The alkali metal that gives a yellow color during a flame test is:
Correct answer: B. Na
- A. Ba
- B. Na
- C. K
- D. Cs
- E. Li
Explanation
Sodium (Na), an alkali metal from Group 1, gives a bright yellow flame during a flame test. The yellow color comes from the excitation of sodium atoms, particularly due to the sodium D-line emission at wavelengths around 589 nm. When sodium ions are heated in a flame, their electrons get excited to higher energy levels and then fall back to lower levels, releasing energy as visible yellow light. This test is so sensitive that even trace amounts of sodium can make the flame appear yellow.
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About s-Block and p-Block Elements
The s and p blocks are studied through their valence-shell configurations, periodic trends and characteristic chemical properties. Work covers the reactions of Group I and Group II elements, the behaviour of Group IV elements, and how atomic size, ionization energy, electronegativity and metallic character change across periods and down groups.
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