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Make Glowing Water
In this science experiment, kids make glowing water while exploring phosphors and UV radiation.
The water in this experiment glows under a black light because it contains phosphors extracted from the highlighter ink. Phosphors are chemicals that absorb then release energy from light. The phosphors in this experiment are “fluorescent,” meaning they release their light quickly and don’t retain a glow over time. When phosphors release the light slowly and create a lingering glow, like with glow paint or glow stars, this is called “phosphorescence.”
Using a black light is a great way to demonstrate phosphors. A black light emits ultraviolet radiation type A, or “UVA” radiation. This is similar to the ultraviolet radiation type B (“UVB”) that comes from the sun, but is not harmful. (When you look at a black light, you will see a purplish glow, but this isn’t the UVA radiation. The UVA radiation is there, but it is invisible.) When UVA radiation shines on things containing phosphors, the phosphors absorb the invisible light and turn it into visible light – that’s the glow you see in the water!
Materials
- Water - 4 cup total
- Yellow highlighter marker - 1 total
- Blue or green highligher marker - 1 total
- Black light - 1 total
Instructions
Carefully open the end of each highlighter, pull out the soft ink insert and cut it open. Place both in 4 cups of water and allow to soak for at least 10 minutes.
Tip: If you make this in a recycled 2 liter bottle, you’ll be able to pour out what you need easily, and store what you don’t need for later.
To make your slime glow, head into a dark room (or make your own bat cave under a table with blankets!) and shine a black light on the water.
Fluorescent water can be used in all kinds of cool science projects -- essentially, it will allow you to make anything that has water as an ingredient glow!
