Glow In the Dark Chemicals
The exoskeleton of scorpions contain phosphors, which are chemical that can absorb high energy photons of invisible UV light and emit lower energy photons of visible light. Photons are particles of light. The colors of visible light, red, orange, yellow, green, blue, indigo, and violet have photons of different energy. The color of the glow depends on the energy of the photons.
The phosphors in scorpion exoskeletons are fluorescent, meaning the chemical only glows as long as it is receiving high energy UV photons. These phosphors are called fluorescent phosphors.
Vaseline (petroleum jelly) contains chemicals that exhibit fluorescence when excited with black light (UV light).
Discover This For Yourself
Use Vaseline (petroleum jelly) to draw a picture on your hand, such as the smiley face shown in the photo. Then, in a darkened room, shine a black light on your hand.
CAUTION: DO NOT SHINE BLACK LIGHT INTO YOUR EYES. IT COULD PERMANENTLY DAMAGE YOUR EYES.