Question

During flame test colour imparted by sodium metal is:
(a) Violet
(b) Red
(c) Green
(d) Yellow

Answer 1

During flame test, the colour imparted by sodium metal is yellow (d).

• Sodium metal, on being subjected to a flame, absorbs heat energy from it.

• The electrons in the metal get excited, and jump from lower energy levels to higher energy levels.

• The electrons are not stable in this excited state, so they jump back to their lower energy levels.

• While jumping back, the electrons release the absorbed heat energy in the form of light.

• This emiited energy falls in the visible range of 577 - 597 nm wavelength in the spectrum.

• This range of wavelength represents the yellow light of the spectrum. Therefore, sodium metal burns with a yellow colour during flame test.

Answer 2

(d) Yellow

Explanation:

When sodium metal is subjected to flame test, the metal gets heated, the electrons are excited when they absorb the heat energy. Since the electrons are not stable in this excited state, they tend to go back to the lower energy state. In the course of this transition, the electrons release the heat in the form of light. The light so emitted is yellow in colour.

During flame test colour imparted by sodium metal is yellow. Option D is the answer.