Why do some metals glow when burning in a flame?

1 Answer
Oct 25, 2015

The radiation that some metals emit falls inside the visual spectrum so we are able to see colours.

Explanation:

When faced with a burning flame, the electrons take energy to go to higher energy levels and emit radiation on their way back to lower energy levels.

Metals such as Na, Ca, Sr, Ba, Cu give out radiation with frequencies inside the visual spectrum. so we are able to see them.

But metals such as Mg emit radiation in the UV area and since human eye is not sensitive to UV radiation, we don't see any colour when a salt of Mg is faced with a burning flame.

Watch this video of the flame test - credits to this video's owner