Science magic tricks, secret writing, petri dish snacks – a science party is a perfect blend of the “wow factor” and hands-on fun. Choose some projects to present as demonstrations and others that everyone can do. Have an adult pretend to be a “mad scientist” and do the demonstrations. Order lab coats for guests to lend credibility and serve as a fun party favor. 

Mad Scientist Demonstrations

The following projects are amazing to watch. Put a little dramatic flare into your demonstration and you'll have a captive audience! These projects require adult supervision.

Collapsing Cup

Watch a Styrofoam cup disappear before your eyes! You can find acetone at a hardware store, or buy it in a small quantity from us. It is very flammable, so keep it away from all flames and use it in a well-ventilated area.
Click to watch video
>> Watch our video demonstration and then try it yourself!

What You Need:

What You Do:

  1. Set the cup in the middle of the pie tin.
  2. Carefully pour about a tablespoon of acetone into the cup.
  3. Watch the reaction!

What Happened:

Styrofoam is mostly air, trapped in place by the polymer polystyrene. A polymer is a very large molecule formed by repeated patterns of chemical units strung together in long chains. The acetone dissolves the long polymer strands in the Styrofoam, allowing all the trapped air to escape. Without air, the cup is just a blob of polystyrene on the bottom of the dish! You can pour off the excess acetone and let the blob of polystyrene dry into a hard lump of plastic.

Mystery Pitcher

There's a lot of opportunity to really ham it up when you do this demonstration! Put on a show of being mysterious by showing the empty pitcher and having a guest fill it with water to prove you haven't added anything to it. Then watch them say “wow” when you change the water into “pink lemonade!” (Make sure no one tries drinking any, though!) Watch this project video for a preview. The video doesn't use an opaque pitcher, but you'll want to for your party.)

What You Need:

What You Do:

  1. Before your guests arrive, prepare the glasses. In the first glass put a little less than 1/8 teaspoon of sodium carbonate, in the second put 6 drops of phenolphthalein solution, and in the third put three dropper-fulls of vinegar.
  2. Add a few drops of water to the first glass and stir to dissolve the sodium carbonate.
  3. When it's time to do the demonstration, fill all the glasses with water from the pitcher, then pour all of them back in the pitcher except for the glass with vinegar.
  4. Refill the remaining four glasses – the water will be hot pink!
  5. Now pour all five glasses back in the pitcher. Refill the glasses one last time—the liquid will be colorless again!

What Happened:

Phenolphthalein is a pH indicator that turns colors in reaction to bases. When you poured the four glasses back into the pitcher, the phenolphthalein reacted to the sodium carbonate, a base, and turned the solution to pink “lemonade.” To change it back to “water,” all you had to do was add the acidic vinegar, which lowered the pH and turned the phenolphthalein colorless again.

Hands-on Ideas for Party Guests

Spread out a disposable plastic tablecloth, pass out some lab aprons, and let your guests get to work! Here are a few fun projects for party-goers:

Magic Writing

Everybody loves secret messages! With adult supervision, let party guests write a note for another guest on white paper using a Q-tip dipped in phenolphthalein solution. Once everyone has finished their message, pass the notes and let the recipient spray the paper with Windex. The message will appear bright pink! Phenolphthalein is a pH indicator that turns pink in the presence of bases, like Windex. Find other ways to write secret messages in our invisible inks project.

Instant Solid Powder

Let each guest get in on the mad scientist action with a little instant solid powder. Pour a little into a cup of water, and it turns into a solid instantly! The change is swift and dramatic, especially when you turn your cup upside down and nothing falls out! Add a little salt and it instantly becomes liquid again. A great project for kids to experiment with different variables – amount of powder, temperature of water, etc. (See kit below.) 

You can also do projects that only require household items, like making slime or quicksand.

Party Refreshments

Make edible bacteria cultures with jello and candy

Edible “Bacteria” Cultures

Petri dishes are used in a science lab to grow bacteria cultures on a gelatinous substance called agar. Mimic their scientific use by making Jell-O and pouring it in clean petri dishes to set up. You can then use small candies like Nerds to create “bacteria colonies” on the surface of the Jell-O.

Glow-In-The-Dark Jell-O

You can do this as a variation of the Jell-O petri dishes, or make separate glowing “jigglers.” To make glowing Jell-O, use tonic water instead of regular water. Tonic water contains a chemical called quinine which fluoresces, or glows, under ultraviolet light. When your Jell-O is firm, shine a black light on it and watch it glow blue. If you don't like the taste of quinine, try using half tonic water and half tap water.

Dry Ice Punch

Add a new twist to your punch by adding some dry ice, available at grocery stores. This looks very cool, as billows of “fog” will roll off your bubbling punch, and the dry ice will make the drink carbonated! Dry ice is frozen carbon dioxide, and it is very cold—110 degrees below zero! This can cause severe thermal burns, so make sure you follow these guidelines:

  1. Always have an adult handle dry ice. Use tongs and insulated gloves.
  2. Make sure no piece of dry ice gets into someone's glass. If possible, put one large block in the punch bowl, not lots of little pieces. Have an adult do the serving; you can serve it by pouring it through a strainer to catch any pieces of ice. (Unlike water ice, dry ice will sink, making it easier to avoid when serving.) You can also wait to serve it until all the dry ice has sublimated (changed from a solid to a gas).

Science Links

Get even more ideas for a science party, including invitations and decorations, at About.com.

Download this party-planning checklist to help you gather the supplies you'll need.

See another fun party demonstration with this egg-in-a-bottle project video.