Hello, Hello. It’s me again Jess with yet another day of bringing the spooky from Halloween and the Science from STEM to celebrate Halloween - the spookiest holiday ever.
So, please, park your brooms at the door, and let’s get spooky together!
On our third day of Halloween Week Spooky Science, let’s create something that is a favorite all through the year. Yay, you guessed it - slime. But not any ordinary slime but a glow-in-the-dark kind. Isn’t that fun? Let’s learn about why some things glow in the dark. Do you know about phosphor and the role it plays in making things glow in the dark.
There are some ways things can glow in the dark - fluorescence and luminescence are some of these.
Fluorescence is when something glows under a black light, but it does not glow anymore if you take the black light away.
Black lights give off harmless and highly energetic ultraviolet rays that are invisible to humans. Some fluorescent substances absorb ultraviolet light and re-emits this at a different wavelength making the material glow. Phosphors is the material that glows under the black light.
Phosphors emit light in response to radiation. A phosphor will convert the radiation into light. This is what happens with tonic water. Tonic water has quinine containing fluorescent molecules that will glow in the dark under a black light.
Another way that things can glow in the dark is called phosphorescence. These are the substances that charge under a regular light or sunlight, and when you turn off the lights, they start glowing.
The science behind this glow-in-the-dark is quite interesting. When we expose the glow in the dark object to light, molecules in the paint absorb photons in the exposed area. This excites the electrons to a higher electronic excited state. When the lights are turned off, it radiates a photon as the electron returns to a lower energy state. Eventually, the electrons lose their energy and their glow.
Ready? Scared? Go!
Materials:
- EVA foam (whatever color you want, I used black for more of the Jack-o’-lantern style
- Glue
- Food coloring or paint (colors of your choice, but orange is so pumpkin-like)
- Slime activator (if you want) or
- Contact lens solution and baking soda.
Now, for the glow-in-the-dark part, we can use a lot of things. Choose the one you think is easiest to get
- Glow-in-the-dark powder
- Glow-in-the-dark acrylic paint
- Glow-in-the-dark glue (if you choose this one, you can replace the regular glue for this one)
In my case, I chose the glow-in-the-dark powder and glue, and I will be making two different slimes.
How to?
First, cut off pieces of your EVA foam in the shapes of your Jack-o’-lantern face.
Now in a bowl, pour the glue. Consider the amount of slime you want to make, but also consider the other materials proportional to it.
I used 1 cup of glue. Use the food coloring now and mix well into the glue. If you are using glow-in-the-dark powder, use it now with the food coloring.
Now slowly add in the the baking soda and contact lens solution. The baking soda will make it grainy and thicker, and the contact lens solution will activate your slime, making it stretchy. So little by little, keep adding the contact lens solution until you find the ‘stretchiness’ you want, but also add the baking soda to make it a little bit more solid. Don’t add too much baking soda, as you will make it too grainy.
If you wish, you can mix the baking soda and the contact lens solution in a separate bowl and make your own slime activator. The proportions are ½ teaspoon of baking soda to 3 tablespoons of contact lens solution.
I find it easier to add them separately, as I have more control of my material.
If you choose to use a slime activator, after the coloring of your glue, just add the slime activator directly into your mixture until you reach the desired ‘stretchiness’.
If you use glow-in-the-dark glue; use it at the first step instead of using regular glue.
If you have a black light, you can see the glowing. But you also can charge the slime close to the light, then turn off your lights to see it happening.
Add the jack-o’-lantern shapes to your slime and make creepy and gooey faces. If you put your slime over a bottle or tube and add your face pieces, you will have an effect like the face is melting.
Pretty cool, right?
I think so too! After you’re done, keep your slime in a plastic bag, and you can play with it anytime you want, even after Halloween.
I hope you guys enjoyed this gooey-face-melting-glow-in-the-dark experiment!
Pumpkin wishes and candy corn kisses, and we will meet again tomorrow!
Jess
