Hello Aspirant

Chemiluminescence comprises of two words that are chemical and luminescence. Luminescence means emission of light and Chemiluminescence means emission of light due to the chemical reaction. Or it is simply a electrochemical radiation generated by the release of a energy in chemical reaction.

It is shown by white phosphorus because it is slowly oxidised at room temperature which emits the faint greenish glow. In this chemical reaction if white phosphorus formation of excited reactive intermediate (PO)2 and HPO takes place which are responsible for emission of that faint greenish glow.

I hope this information helps you.

Good Luck!!