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My middle daughter recently turned 8, and she asked me if we could do science experiments at her birthday party. Despite running a STEAM activities for kids blog, surprisingly we’ve never done a science-themed birthday party before. I was very excited to plan which STEAM activities from my blog to include in the party. I worked with my kids to decide which activities would be best for a group and the most fun for all the kids, and we came up with a great mix of six activities.
We had perfect weather (in the low 80s), so were able to keep the kids outside for the whole party, which I recommend (weather permitting) when doing science experiments with a group of kids. It makes clean up much easier (just hose everything down), and I spent less time stressing about spills and messes.
If your weather doesn’t permit an outdoor party, you can easily do everything inside (except Puncture a Bag of Water without Spilling a Drop – this activity leaks water and could make a slip hazard). Just put down a plastic table covering and you will be good to go! We did Elephant toothpaste inside, and since I did it a disposable baking pan there was no mess.
It wouldn’t be science without a few mistakes and a few of our activities didn’t go as planned (I’ll explain as I go over each activity below). The great thing about science is you can still learn and have fun when things don’t go as plan. Yes, I said it’s a great thing, because it teaches you to analyze what went wrong, and try again. We are learning resilience through our mistakes, so if something goes wrong brush it off, remember it’s part of the scientific process, and move on!
Four of the birthday party STEAM activities were hands on for the party guests, and two of the activities were exciting science demonstrations performed by an adult (me). I suggest having at least two adults available to help with all the activities. I also recommend a group size no larger than 10 kids for a science party. We had around 15 kids total and it worked out ok, but I think it would have gone even better with a slightly smaller group.
My daughter’s party was a whooping 4 hours long! Yes, this was a long time, but the kids had plenty of time to play together, be silly, eat dinner, do a piñata, eat cake, and do the science experiments in between. If you plan a shorter party, you probably would need to cut down the number of activities, or give less play time in between activities.
Did you know I have a blog post on how to Make a Piñata? I wish I had planned ahead so we could have made our own piñata for the party, but we missed out this year. The instructions to make a piñata can be found in the blog post and in the new Birthday Party STEAM Activity Printable Pack. Not only is a it more fun to make your own, you can personalize it by decorating it however you like, and it’s less expensive than purchasing a piñata (our premade piñata cost around $20).
In the sections below I will give an overview of the six STEAM activities we did at the party and explain what went well and what didn’t. I link to each of the original blog posts so you can read exactly how to do each experiment.
Birthday party STEAM Activity 1: Puncture a Bag of Water Without Spilling a Drop
I told the party guests that this was a science version of pin the tail on the donkey! I filled a gallon sized Ziploc bag about 3/4 full with water. We gave all the kids very sharp pencils (here is a link to the pre-sharpened pencils I bought on Amazon). I held up the bag filled with water and asked the kids to take turns puncturing the bag with their pencils without spilling water. The rules were if they made it leak water, they are out. To all the kids’ surprise, no one got out! The party guests were all able to puncture the bag without spilling water. The kids were shocked and amazed.
Then for the fun part, I asked them pull out their pencils, and chaos ensued as water began spraying out of the bag. The kids loved this and some (including all 3 of my kids) were purposely going close to the bag to get wet!
We repeated this activity five more times using six gallon size Ziploc bags total because the kids couldn’t get enough and wanted to keep doing it over and over. I would call this activity a complete success and probably the most popular activity at the party!
To get all the details on how to do this activity you can read my original blog post linked here, and you can find this activity in my newest printable “8 Easy and Fun Birthday Party STEAM Activity for Kids” which you can purchase from my Shop.
Birthday Party STEAM Activity 2:
Soda Geyser
Next up was a crowd pleaser demonstration of the Soda Geyser. I knew this activity would be a hit, so we bought four 2L bottles of Diet Coke and a 6 pack of Mentos rolls, so we could repeat the activity up to four times. All the kids wanted to participate, but when you have a large group it’s best if the adults (and maybe the birthday child) demonstrate while the guests observe.
For our first demonstration, I let my daughter help me by dropping the mentos into a paper funnel (I created this by rolling a piece of paper into a funnel shape just smaller than the Diet Coke bottle opening). The Mentos dropped through the funnel into the Diet Coke bottle, and then my daughter and the other kids in the front jumped right into the Diet Coke explosion and played with it. They enjoyed this, but if you don’t want all the party guests to get covered in Diet Coke, then I recommend adults demonstrate with the party guests sitting a few feet away to observe the geyser.
We continued on with the kids getting soaked in Diet Coke for the first three demonstrations, then I finally took control and did a solo demonstration for our final bottle of Diet Coke. The kids had smashed the first three bottles in their excitement, and I needed at least one bottle in good shape for the upcoming Elephant Toothpaste demonstration.
The solo demonstration worked well, and I think the kids got to see the geyser better, because they weren’t as focused on rushing in to play with the exploding Diet Coke. You can do this inside using a disposable baking pan (the pan will contain the Diet Coke overflow).
To get all the details on how to do this activity you can read my original blog post linked here, and you can find this activity in my newest printable “8 Easy and Fun Birthday Party STEAM Activity for Kids,” which you can purchase from my Shop.
Birthday Party STEAM Activity 3:
Color Changing Butterfly Pea Tea
This was a great way to calm the birthday party guests down after the excitement of the Soda Geysers. This is when you will need a few adults to help out at the party. I went inside to prepare the tea while my husband remained outside supervising the kids as they played. The inside prep time took me around 15 minutes while I boiled water, steeped and sweetened the tea, put ice in the cups, then divided the tea between 15 cups, and cut lemons.
This is one of the activities that didn’t work out as well as planned. I should have bought clear plastic cups to use for this activity so the kids could see the color change better. All I had were large red Solo cups. Since these cups are so big, I ended up giving the kids too large of servings of the tea (I filled the red Solo cups about half-full with tea), and I ran out of ice while filling them, so their tea was warm instead of iced.
I only bought enough lemons for the party guest to have half a lemon each, but since there was so much tea in the cups, the color change wasn’t drastic with only half a lemon. They could have used at least a full lemon each to make the tea turn pink. Their teas still changed color from blue to purple, and the kids loved it. I think I am the only one who was upset knowing it could have turned pink if we had enough lemon juice (and/or I gave them smaller serving sizes).
The kids liked tasting their purple tea (most didn’t like it, but that’s ok!), and they all had a great time squeezing the lemons and watching the color change, so despite the small hiccups, I’d call this activity another success!
To get all the details on how to do this activity you can read my original blog post linked here, and you can find this activity in my newest printable “8 Easy and Fun Birthday Party STEAM Activity for Kids,” which you can purchase from my Shop.
Birthday Party STEAM Activity 4:
Easy Slime
This another activity at the party that ran into some problems. I wanted each child to make the slime themselves, so I didn’t prep the ingredients beforehand. With such a large group, I became overwhelmed serving each child the ingredients because everyone wanted help right away. I started off carefully measuring the ingredients and reading my recipe, but it was taking too long, so I started winging it and guesstimating the ingredient amounts.
Since I put down my recipe we left out the baking soda (I didn’t notice at the time). We kept adding more saline solution (activator) and more glue, but nothing worked.
We eventually restarted and tried again (I still didn’t think to re-read my instructions to see if I was missing something), but I eventually ran out of glue and saline solution so we had to stop. The slime never got to the right consistency for anyone. It was too sticky, or too runny, and it just never came together as it is supposed to or as it had done for me in the past.
I spent the whole night after the party thinking about what could have gone wrong. Eventually I re-read the instructions, and that’s when I realized we forgot to add the baking soda! That was a lesson learned for me to be sure to check the instructions while doing the activity, so we don’t accidentally skip an important ingredient or step.
Despite the slime not working out, the kids still had so much fun attempting to make the slime: mixing it, choosing colors, and getting messy. And in the end, I bet many of the parents were happy that their children weren’t coming home with slime. 😉
To get all the details on how to do this activity you can read my original blog post linked here, and you can find this activity in my newest printable “8 Easy and Fun Birthday Party STEAM Activity for Kids,” which you can purchase from my Shop.
Birthday Party STEAM Activity 5: Elephant Toothpaste
This is another fun demonstration that an adult can perform for the party guests. Everyone sat around our table while I did the demonstration. I asked the birthday girl to select 2 colors for the stripes to color the elephant toothpaste, and the kids were all excited to see what would happen. I reused a 2L bottle from the Soda Geyser experiment and put the bottle inside a large disposable pan for easy cleanup.
After the demonstration, I explained to the kids that this was an exothermic reaction, meaning it gives off heat making the elephant toothpaste very hot. They wanted to feel it, but I didn’t have gloves for everyone (and you cannot touch it without gloves because the 40 volume clear developer is corrosive). I wiped off the outside of the bottle (there was still elephant toothpaste inside it) and let the kids touch the outside of the bottle to feel the heat from the experiment. This was very exciting to them, they couldn’t believe how warm it was!
This experiment went perfectly for us and the party guests loved it! I was demonstrating and my husband was helping with the party guests and talking to parents, so unfortunately we didn’t take any pictures of this activity at the party. It looked so cool (we used green and blue stripes), so I really wish I did have photos. The picture below is from my original blog post, which was 4 years ago. It’s my daughter who just had her 8th birthday in the picture, she was so little! I love that we’re still doing science experiments together at home after all these years.
I have received a few questions on my blog post about problems that have come up while doing this experiment. Here are my tips to help make this activity a success: use 40 volume CLEAR developer (I bought mine at Sally Beauty Supply, but it’s also available on Amazon), and make sure to use active dry yeast and activate it in warm water (it will get foamy when activated).
To get all the details on how to do this activity you can read my original blog post linked here, and you can find this activity in my newest printable “8 Easy and Fun Birthday Party STEAM Activity for Kids,” which you can purchase from my Shop.
Birthday Party STEAM Activity 6: Foaming Balls with a Hidden Surprise
This activity requires some prep work. Our party was in the late afternoon so I prepared the baking soda balls the morning of the party. I’d recommend preparing the balls the night before the party, so you are not as busy on the day of the party and to give them time to dry. I added too much food coloring to the dough, and ended up dying my hands blue. It took many washes to get to the blue out, but my hands were back to normal by the time the party started. I recommend using minimal amount of food coloring and/or wearing gloves while forming the balls to prevent staining your hands. Food coloring is optional – the balls will be white without the food coloring – you can call them snowballs for a winter party!
We found some cute small erasers shaped like food (here is a link to similar erasers on Amazon) to use as the surprise in the balls. The kids loved their erasers, so I think this was a good choice. We also made this a party game – we hid a quarter instead of an eraser in one of the balls, and told the party guests that whoever gets the quarter wins a chocolate bar (this was my daughter’s idea and was an exciting twist for the party guests).
I used the red Solo cups again for this activity (clear plastic cups would have better for this activity too), and filled them about 1/4 full with vinegar. I would use as little vinegar as you can in the cups. Even 1/4 full was too much and many of the cups bubbled over spilling vinegar onto the table. We did this outside, so I didn’t mind the mess. We just hosed the table and concrete below it with water after the party was over.
It was very exciting for everyone to see the baking soda and vinegar reaction bubble in their cups when they dropped in the balls. The kids loved looking for the prize in their cups after the bubbles ended, and they were all happy with the erasers. The one lucky kid who found the quarter was thrilled with the chocolate bar prize!
It’s important for me to mention that these balls do crumble easily, so be sure to tell kids to handle them carefully. I made a few extra balls just in case they fell apart, and we needed about 3 or 4 extra balls. I would recommend making several extra to have on hand just in case a few crumble before they are used.
To get all the details on how to do this activity you can read my original blog post linked here, and you can find this activity in my newest printable “8 Easy and Fun Birthday Party STEAM Activity for Kids,” which you can purchase from my Shop.
My daughter and her friends had a great time at her science-themed birthday party. Would you host a similar party? I highly recommend it, but I also recommend to plan it when you will have a day off the next day to recover 😉 – I definitely need a rest day after the party!
If you want to make the planning easy I recommend buying my new Birthday Party STEAM Activity pack. This pack has these six activities (plus two more), with all the details you need and nothing you don’t. You just have to print the activity pages, and then you are ready to go with the list of materials and step-by-step instructions for each activity in your hand.
Good luck planning an epic science birthday! Let me know any questions you have and tell me how the party your party goes in the comments below.
