What color comes to mind when we talk about radioactive elements? Many people probably think of green. But the truth is that very few radioactive substances glow on their own: the luminescence (or radioluminescence) comes from the interaction of the emitted particles with the surrounding materials. This glow can be yellow, blue, and yellowish... But for some reason it is green that we tightly associate with radiation.
The culprit of this prejudice is most likely the radioactive metal radium. At the beginning of the 20th century, science made great strides in exploring the nature of radiation and discovering new radioactive elements. Curiosity and the desire to innovate led people to use radioactive substances, for example, in the mass production of household goods, especially the science of the time did not yet consider radioactive radiation as something dangerous to humans.
One of the elements of greatest interest was radium. It was used to make luminous paint, where radium radioactivity created a green radioluminescence. It's so convenient: to paint the necessary places with radium paint, which will glow in the dark for many years without any problems!
Such paint was used to highlight the numbers and hands in wrist and room clocks, on instruments that had to be used in the dark, in vehicle cabins, and even in some designs. When mankind finally realized the danger of radioactive radiation, everyone began to get rid of things with radium dye as a matter of urgency. And the ominous green glow became forever associated with the word "radiation" in the public consciousness.