My youngest son requested a science-themed party for his sixth birthday this past February, but because our small apartment couldn’t hold the 20 kindergarteners and many messy experiments on his list, he agreed to wait until spring so we could spill into our backyard. We rewarded our patient scientist by adding a few even messier experiments to his plans!
Balloons were our only decorations — quick and easy!
1. Decorating favor bags while waiting for everyone to arrive
I bought inexpensive canvas totes from Muji and set out cups of fabric markers. (Before the party I slipped scrap cardboard inside so the pens didn’t bleed through.) I like having a quiet activity set up so that kids can work individually as other kids are arriving. After the party, I put their safety glasses, Insta-worms (our first “experiment”), deflated windbags (see below), a toy magnifying lens, and a little treat into their bags.
We purchased this kit and extra squeeze bottles from Steve Spangler Science. The Steve Spangler website explains Instant Worms: “Explore the science of building polymers by cross-linking long chains of molecules. The process of making Instant Worms is faster and easier than the classic Slime recipe and it happens the very second the two liquids mix.”
We premixed the activator solution into separate cups for each kid. They shared the squeeze bottles full of “worm goo” which we tinted before the party using food coloring. We set out bowls of Popsicle sticks so the kids could easily pull the worms out of the solution. I pre-labeled sandwich bags with the kids’ names so they could take their worms home.
3. Science Show
Everybody headed out to the backyard with their safety goggles where my husband Fred demoed three different experiments — all super easy to prep and with a good wow factor.
Act 1: Self-Inflating Balloon
Before the Party: Pour four tablespoons of vinegar into a clean bottle. Use a funnel to fill a balloon with one tablespoon of baking soda. Be sure that the balloon falls to one side as you carefully slip its opening over the neck of the bottle so no baking soda gets in to the bottle.
At the Show: Lift the balloon to let the baking soda fall into the bottle. The balloon will inflate all by itself!
The Lesson: When the baking soda and vinegar come into contact, they form a gas: carbon dioxide. This gas fills the bottle and can’t escape, so it rushes into the balloon, inflating it.
Act 2: Egg in a Bottle
Before the Party: Peel a hard-boiled egg and set it on the neck of a glass bottle. The neck should be slightly smaller than the egg. A milk bottle is a good size.
At the Show: To add to the anticipation, Fred had an extra milk bottle with a uncooked egg on the neck. He pretended that he thought he could get it into the bottle, smashed it and made a mess — which the kids loved! He then took the other bottle with the hard-boiled egg, lifted the egg, and dropped two lit matches into the bottle. He quickly set the egg on top again. As the flames went out, the egg was sucked into the bottle with a loud “POP”! The kids were very surprised.
The Lesson: Before you insert the matches, the air on the inside and outside of the bottle are exactly the same. As the fire burns, it uses up the oxygen inside the bottle, creating a vacuum. (You can explain that the air inside is thinner than the air outside of it and the higher pressure on the outside of the bottle actually pushes the egg in.)
Act 3: The Grand Finale: Mentos Geyser
Before the Party: All you really need are a package of mint Mentos and a two-liter bottle of Diet Coke (any soda will work but diet leaves a less sticky mess afterward). We purchased this loading tube from Steve Spangler which gives you more control and time to get away when dropping in the Mentos.
At the Show: Again, Fred built up the suspense (and lowered expectation — so the kids were really surprised) by dropping different items in a few extra bottles of soda: grapes and salt, which each caused just a little bit of fizzing and gurgling. When he used the Mentos, the kids couldn’t believe it. It shot up to the second story of our building (see picture, above right). Fred was soaked!
The Lesson: From Steve Spangler Science: “Each Mentos candy has thousands of tiny pits all over the surface. These tiny pits are called nucleation sites — perfect places for carbon dioxide bubbles to form. As soon as the Mentos hit the soda, bubbles form all over the surface of the candy. Couple this with the fact that the Mentos candies are heavy and sink to the bottom of the bottle and you’ve got a double-whammy. When all this gas is released, it literally pushes all of the liquid up and out of the bottle in an incredible soda blast.” More info here.
Instead of applause … water balloons! Scientist Dad was very messy, so we “helped” him clean up by throwing water balloons at him. What a great dad!
After some pizza indoors (and freeze dancing — even scientists need to let loose!) the kids headed out again to play with these windbags that I also bought from Steve Spangler.
5. Laboratory photo booth
During the party, we snapped pictures of the guests in lab coats in front of a laboratory backdrop that my sons and I painted a few days before the party. We used this app to get the photo booth effect.
We loved the way the pictures came out and sent them to all the families in their thank you notes.
The birthday boy requested dirt and worms (a.k.a. ground chocolate wafers and gummy worms) on top of his cupcakes in honor of our homemade slime worms. We used our favorite recipe for chocolate cake. For the cupcake topper, I printed a picture of my son in his lab coat onto card stock, cut it out, and glued it to a wooden skewer. I stuck it in along with a toy magnifying lens.
Better late than never. Messy science was a big hit and really easy to prepare!