Top 5 Halloween Science Experiments
How to make really spooky Halloween decorations
Halloween is coming… and if your costume is ready, it’s the perfect time to think about your decorations – how to make your celebration unforgettable. Here are 5 simple experiments that will help make your Halloween truly creepy!
Foam Jack-O’-Lantern
To make foaming pumpkin, you’ll need:
- hydrogen peroxide, H₂O₂ (any strength will do, but the less concentrated it is, the less dense your foam will be) (1/4 cup or 60 mL);
- water (1/8 cup or 30 mL);
- yeast (1/2 oz or 14 g);
- any food coloring (1 tsp or 5 mL);
- liquid dish soap (1 Tbsp or 15 mL);
- 3 cups or small bowls;
- jack-o’-lantern (you won’t need candles, but keep the top – it will serve as a lid).
What’s next?
- In the first cup, mix the hydrogen peroxide, liquid soap, and food coloring;
- In the second cup, mix the yeast with some water;
- Put the empty third cup into the pumpkin and pour in the contents of the other two cups: first the soap solution, then the yeast mixture;
- Quickly put the lid on the pumpkin: this reaction will produce a lot of foam.
When hydrogen peroxide decomposes, it produces oxygen and water. Normally this is a relatively slow process, but yeast speeds it up dramatically. The rapidly-generated oxygen whips the liquid soap into a thick, voluminous foam. There’s so much foam that it forces its way out of the jack-o’-lantern!
Jack-O’-Lantern in Green Flame
To make a pumpkin bathed in flame, you’ll need:
- copper(II) chloride dihydrate, CuCl2 (1/2 oz or 15 g);
- ethanol, C2H5OH (96%) (1 cup or 240 mL);
- toilet paper (or dry napkins);
- lighter;
- spray bottle;
- jack-o’-lantern.
What’s next?
- Mix the salt crystals with the alcohol (the salt will partially dissolve, creating a greenish solution);
- Insert the roll of toilet paper or crumpled dry napkins into the pumpkin, then thoroughly wet with solution;
- Spray the pumpkin from all sides with the alcohol solution – this will make the experiment much more impressive.
When ignited, the alcohol burns green. Why is this? The green tint is the result of the copper ions from the salt. When heated, they absorb energy from the flame and later release this “extra” energy as green light. Conduct this experiment outside and don’t leave your pumpkin unattended.
Observe fire safety precautions when conducting this experiment!
Smoking Jack-O’-Lantern
Want to add some variety to Halloween’s most renowned symbol – the Jack-o'-lantern? Just use plain old glycerin!
To make “smoldering” pumpkin, you’ll need:
- glycerin, C₃H₅(OH)₃ (1 tsp or 5 mL);
- 3 small candles;
- 1 aluminum can;
- scissors;
- pipette (to transfer glycerin);
- jack-o’-lantern (be sure to save the top - it will serve as a lid!).
What’s next?
1)Set a few candles in the pumpkin and light them; 2) Cut an aluminum can to make a stand as shown in the video; 3) Drip some glycerin into the hollow of the can; 4) Place the lid (saved from when you carved your pumpkin) on your jack-o’-lantern.
Why does the glycerin vapor appear? The candles warm the aluminum, and the glycerin begins to vaporize in the heat, turning into white, smoky clouds. This makes for a truly terrifying pumpkin – it’s both glowing from the candles and releasing ominous smoke from its eyes and mouth!
Observe fire safety precautions when conducting this experiment!
Fluorescent Jack-O’-Lantern
To make fluorescent pumpkin, you’ll need:
- ethanol (40%) (1/6 cup or 40 mL);
- fluorescent highlighter (you’ll need its cartridge);
- cup;
- paintbrush;
- spray bottle;
- blacklight
- jack-o’-lantern or pumpkin
What’s next?
- Remove the cartridge from the highlighter and rinse it thoroughly in alcohol to extract its dye;
- Use the paintbrush to apply the alcohol solution to the pumpkin and wait for the alcohol to evaporate;
- Turn on your blacklight and enjoy the effect: the whole pumpkin will glow!
This glowing pumpkin will look especially creepy and impressive under a blacklight with the room lights off!
Why does the pumpkin glow? Many markers contain dyes that glow in ultraviolet light. This interesting phenomenon is known as fluorescence.
Fake Blood
The ingredients for this experiment can be found in any kitchen or convenience store!
To make fake blood, you’ll need:
- water (1 1/4 cups or 300 mL);
- sugar (8 oz or 230 g);
- citric acid or lemon juice (1 tsp or 5 g);
- instant coffee (1 tsp or 5 g, optional);
- food coloring (red and blue) (2 Tbsp or 30 g);
- regular flour (1/8 cup or 20 g);
- small pot or saucepan;
- pumpkin or jack-o’-lantern.
What’s next?
- In the pot, mix water, citric acid, and sugar, and bring to a boil;
- When the solution cools, add the food coloring (red and a few drops of blue). You can also add coffee to make the color more intense.
- To thicken the “blood,” add some flour.
Why does the blood turn out so realistic? Sugar molecules consist of glucose and fructose. Citric acid inverts normal sugar – that is, it makes a sugar syrup that contains not sucrose, but equal quantities of glucose and fructose. This serves to help the blood maintain its appearance over time. The flour has a different purpose – it makes the fake blood thicker. This blood is almost indistinguishable visually from real blood! It can even be used for Halloween makeup; it is completely safe. Just keep in mind that food coloring isn’t always easy to wash off!
