Glowing Pumpkins | Halloween Science Experiment

Glowing Pumpkins – Halloween Science What will make an ordinary jack-o’-lantern even more awesome? How about some glow-in-the-dark pumpkins for a super-cool spin on the traditional pumpkin art?

Glowing pumpkins will really give your friends, family and neighbors “pumpkin” to talk about! Decorate for Halloween with these eerie glow-in-the-dark jack-o’-lanterns.

If you’re a fan of Spangler Science, you know that we love exploding pumpkins — even puking pumpkins. We’ve also found that glowing pumpkins can be just as fun, too! Just add our zinc sulfide Glow Powder to your Halloween pumpkins and you’ll get a spooky Halloween display, without all the mess of carving.

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Experiment Materials

  • Pumpkin
  • Contact paper
  • Glow Powder - Luminous Zinc Sulfide
  • Spray glue
  • Rubber band
  • Thumb tack
  • Aluminum foil
  • Scissors
  • Cup
  • Permanent marker or felt pen
  • Drop cloth or large cardboard box
  • Black light
  • Ventilation mask (if the experiment is not done outside)
  • Empty salt shaker (Optional)
  • Spray-on sealant
  • Adult Supervision

Experiment Videos

Experiment

1

If you are using real pumpkins, start by wiping them off with a damp cloth to remove any dirt left over from the pumpkin patch. Once rinsed, dry the pumpkin thoroughly.

2

Draw your pumpkin design on the contact paper and cut each piece out.

3

Peel the pieces off the paper backing and arrange them on your pumpkin.

(Once your design is complete, take your pumpkin outside and place it on the drop cloth. If you need to do the experiment indoors, make sure that you are in a well-ventilated area and place the pumpkin in a cardboard box.)

4

Prepare your glow powder by either putting it into an old saltshaker or by creating your own shaker.

(To create your own shaker, place some glow powder in a cup and cover the cup with foil.  Put a rubber band around the foil to hold it securely on the cup, then poke holes in the top using the thumb tack.)

5

Spray sections of the pumpkin with the spray adhesive. For best results, hold the adhesive 10-14 centimeters (4-6 inches) away from the pumpkin and spray on a heavy coat.

6

Immediately after spraying on the adhesive, sprinkle the glow powder onto the pumpkin. You may want to tilt the pumpkin to get it evenly covered.

7

Continue spraying and powdering each section of the pumpkin until the entire pumpkin is completely covered with powder.

(Carefully shake off any excess powder as you go and collect the excess Glow Powder and pour it back into the shaker.)

8

After the adhesive is completely dry, spray the entire pumpkin with a sealant to make sure that the Glow Powder stays affixed to the pumpkin.

Let your glowing pumpkin dry and carefully pull the contact paper off. Your spooky Halloween decoration is ready to be “creep”-tastic!

9

Want an extra-bright glow on Halloween night? Arrange your glow-in-the-dark jack-o’-lantern next to a black light. You can use one of our hand-held black lights for a hands-on effect. If your pumpkins are on a front porch or are decorations for a Halloween party in your home, you can replace regular lights with black light bulbs.

How Does It Work

Learning about the science of things that glow requires an understanding of two important terms: fluorescence and phosphorescence. It’s also important to note that not all zinc sulfide glows, but luminous zinc sulfide does!

Fluorescence: This type of luminescence occurs when some form of radiation, such as light, causes an object to glow. For example, fluorescent papers and poster boards glow in the daylight. They may seem to glow even brighter under black light (ultraviolet). In either case, the glow stops as soon as the light is removed. Fluorescent things do not glow in the dark all by themselves. Instead, they require some other form of energy, such as ultraviolet light, to “excite” them.

Phosphorescence: Phosphorescence is just like fluorescence, except that the glow continues even after the light used to excite it is removed. “Glow-in-the-dark” toys phosphoresce brightly in total darkness after being “charged” (or excited) by ordinary white or ultraviolet light.

Our Glow Powder works by absorbing surrounding light energy and then releasing that energy when the lights go out. It is called a “phosphorescent powder.”

So, how does zinc sulfide work? Imagine that an atom looks something like our solar system. The sun would be the nucleus, consisting of positive charges (called protons) and neutral charges (called neutrons). The planets spinning around the sun would be similar to the electrons of an atom in an orbit around the nucleus.

When atoms’ special molecule electrons (such as zinc sulfide) become excited, they move farther away from the nucleus, into higher or more distant orbits. In order to become excited, the electrons must take on energy. In this case, the light provided the required energy to cause the electrons to move to a higher energy level. It’s as if Earth was to move farther away from the sun into the orbit of Mars or Jupiter.

As long as they receive light to energize them, the electrons will remain in their excited states. But when the light used as an exciter is removed, the electrons will slowly return to their original lower orbits. As they do so, they give up the energy that excited them.  This energy is released in the form of light, creating the “glowing” effect.

Glow Powder is the perfect way to get excited about energy and is a great way to celebrate Halloween! Just add glow powder to almost any of our products and you’ll have an eerie new take on your favorite experiments!

Glowing Pumpkins at Your Next Halloween Party 

Glow-in-the-dark jack-o’-lanterns make great party decorations! For another pumpkin bag of tricks and treats, visit our oozing pumpkin experiment. In addition to these glowing pumpkins, don’t miss our other Halloween-themed experiments that demonstrate scientific principles. You’ll find chemistry experiments and food science experiments that will add some “spook”-tacular fun that will be wicked awesome. Visit our online instructions on how to make a tasty witch’s brew and Boo Bubbles with dry ice. For added grossness to your costumes or Halloween décor, add some fake blood. 

DID YOU KNOW?

This experiment was originally presented by Martha Stewart on her daytime show. When Martha wanted glowing pumpkins, she called us for A LOT of our Glow Powder. We loved Martha’s pumpkins so much we had to recreate them for you!

Take It Further

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Did you know?

This experiment was originally presented by Martha Stewart on her daytime show. When Martha wanted glowing pumpkins, she called us for A LOT of our Glow Powder. We loved Martha’s pumpkins so much we had to recreate them for you!