Create a soda & mentos geyser
With adult supervision, set up a bottle of soda and drop Mentos to launch a fizzy geyser outdoors, observing reactions and cleaning up afterward.
Step-by-step guide to Create a soda & Mentos geyser
Step 1
Find a large open outdoor space away from people cars and breakable things.
Step 2
Put on your safety goggles before you start the experiment.
Step 3
Place the unopened bottle of soda upright on flat level ground.
Step 4
Keep the bottle still and do not shake it.
Step 5
Make a candy drop tube by putting a funnel into the bottle top or by rolling stiff paper into a tube.
Step 6
Load 3 to 5 Mentos into the tube so they sit ready to drop.
Step 7
Hold the tube directly over the bottle opening without letting the Mentos fall yet.
Step 8
Step back at least six feet to a safe distance.
Step 9
On the adult's count release the Mentos so they fall quickly into the bottle.
Step 10
Watch from your safe distance and observe how high and how long the fizzy geyser goes.
Step 11
Wait until all the fizzing has stopped before moving closer.
Step 12
Use paper towels or a cloth to wipe up sticky soda from the ground and bottle.
Step 13
Put used paper towels and candy wrappers into the trash bag.
Step 14
Share a photo or description of your fizzy geyser experiment on DIY.org.
Final steps
You're almost there! Complete all the steps, bring your creation to life, post it, and conquer the challenge!
Help!?
What can we use if Mentos, a funnel, or safety goggles are hard to find?
If Mentos aren't available try other smooth hard mints (expect a smaller reaction), use the rolled stiff-paper tube option from the instructions instead of a funnel, and wear snug safety or sports glasses if you don't have formal safety goggles.
Why didn't my bottle make a big geyser and how can I fix it?
If the geyser is weak, make sure you start with an unopened, well-carbonated soda placed upright on flat level ground, hold the tube directly over the bottle opening so all Mentos fall at once on the adult's count, and avoid shaking the bottle before release.
How can I adapt the experiment for younger kids or older kids?
For younger children have an adult load and hold the tube over the bottle while the child watches from the safe six-foot distance and use one or two Mentos for a smaller splash, while older kids can load 3–5 Mentos themselves, vary soda types, and measure geyser height and duration.
How can we extend or personalize the soda & Mentos geyser activity?
Extend the activity by testing different sodas (diet vs regular), changing the number of Mentos, timing and measuring how high the fizzy geyser goes, creating a ground target to aim for, and sharing photos or results on DIY.org.
Watch videos on how to Create a soda & Mentos geyser
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How It's Made: Natural Baking Soda
Secret Formula of Coca-Cola | National Geographic
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How Many Mentos Make the Best Diet Coke Geyser?
Facts about chemistry experiments for kids
🍬 Mentos candies have microscopic pits on their surface that act as nucleation sites, letting CO₂ bubbles form quickly.
🥤 A 2‑liter bottle and lots of Mentos can make a fizzy geyser that shoots several meters into the air — perfect for outdoor demos!
🌍 The Diet Coke and Mentos experiment became a viral internet craze in the mid‑2000s, inspiring countless videos and demo events.
🔬 It's not a chemical reaction — it's a physical process: dissolved CO₂ rapidly escapes when bubbles form on the Mentos surface.
👀 Safety first: always do this outside with adult supervision, wear goggles, and stand back for the big splash.
