Glowing Water Experiment
Glowing water using Black/UV Light and Yellow Highlighter
I did this experiment with young kids and they enjoyed it.
It is very easy and cheap.
Supplies
- Black Light (UV Light) - A bug zapper emits UV light
- Pliers
- Yellow Highlighter
- Spoon
- Clear Glasses
- Water
Optionally:
- Tonic water
- Tonic water contain a chemical (quinine) which contains Phosphors so it will glow with a black light too.
Take the Back Off the Highlighter and Drop Ink in Water
- Get the ink from the Highlighter
- This is easily done by using a pliers
- A needle nose pliers did not work for me.
- After you remove the back cover, drop the ink into a glass of water.
- I used a kitchen glass and tap water.
- Be careful not to stain anything around you.
- I used a spoon to stir it around.
- I recommend holding off on this and waiting until the black light is on.
- Optionally: Have a second glass of water (without the ink) to use as the "Control."
Turn Off the Room Lights and Turn ON the Black/UV Light
Put the ink in the water and stir around.
Science Behind How It Works
A blacklight, also referred to as a UV-A light, Wood's lamp, or ultraviolet light, is a lamp that emits long-wave (UV-A) ultraviolet light and very little visible light.
A phosphor is a substance that exhibits the phenomenon of luminescence; it emits light when exposed to some type of radiant energy
Basically, the Black/UV light (radiation) emits invisible light that excites the Phosphors in the highlighter dye and this in turn, causes the phosphors to emit their own visible light.
Phosphors are in our teeth and fingernails too so the black light make those glow too. They radiate visible light after being energized.
Characteristics:
- type of energy required to be energized
- color of visible light produced
- Length of Glowing time (Persistence)
Directly from wikipedia:
"When a phosphor is exposed to radiation, the orbital electrons in its molecules are excited to a higher energy level; when they return to their former level they emit the energy as light of a certain color. Phosphors can be classified into two categories: fluorescent substances which emit the energy immediately and stop glowing when the exciting radiation is turned off, and phosphorescent substances which emit the energy after a delay, so they keep glowing after the radiation is turned off, decaying in brightness over a period of milliseconds to days."
Other Notes
I noticed the Black/UV Lights filament reflection in the spoon changed colors whether if it was submerged or not.
The phone camera did not pick up the change, but to the human eye it was either purple (above mixture) or red (submerged)
- I'm interested to see what other color highlighters do
- Use Tonic water (I didn't have any on hand)
- Try a better black/UV light (Brighter glow?)
Asking young kids questions:
- Does water glow? (showed them it doesn't)
- Does water glow with a black/UV light (showed them it doesn't)
- Do you think the highlighter will glow?
- What color will it glow?
I also explained the Black/UV light gets Hot.
I attempted to explain why Phosphors make it glow.
References
I first discovered this project on pinterest which lead me to the link below:
https://coolscienceexperimentshq.com/glowing-water/
I figured I would simplify
https://slidetodoc.com/how-glowinthedark-works-all-glowinthedark-products-contain-phosphors/
https://www.todayifoundout.com/index.php/2012/06/how-black-lights-make-things-glow/
https://www.wristband.com/content/the-science-behind-glow-in-dark-toys-materials/