Question: What happens during the process of irradiation?

Matthew Camilleri answered on 20 Nov 2014:

We are constantly being irradiated by the sun, meaning that different waves from the sun, with a varying degree of wavelengths are reaching earth, adn we can see these as colours.

A number of molecules can actually absorb these colours and we will see everything that is reflected back, so if a molecule absorbs green light we wil be able to see it as red.

In some cases when molecules absorb light they become excited and therefore become reactive, and that is what I try to do with my chemicals.