The Most Jaw-Dropping High School Science Experiments, According to Reddit
High school science classes are often where curiosity meets chaos—and sometimes, pure magic. Whether it’s a teacher’s dramatic demonstration or a student project that defies expectations, certain experiments stick in our memories forever. Reddit users recently shared their favorite classroom moments, and the stories range from explosive chemistry to mind-bending physics. Let’s dive into the experiments that left students wide-eyed, laughing, or even reconsidering their career paths.
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1. The Explosive “Elephant Toothpaste” Reaction
One Redditor vividly described their chemistry teacher combining hydrogen peroxide, dish soap, and potassium iodide in a graduated cylinder. The result? A foamy geyser erupting like a “giant blue marshmallow monster.” The experiment, nicknamed “elephant toothpaste,” demonstrates an exothermic decomposition reaction. As the hydrogen peroxide breaks down, oxygen gas gets trapped in the soap, creating a rapid, colorful expansion.
But the real thrill came when the teacher scaled it up. “They did it outside with a trash can-sized container,” wrote another user. “The foam shot six feet high. The principal came running, thinking something was on fire. Best. Day. Ever.”
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2. The Egg Drop Challenge: Creativity vs. Gravity
A classic engineering experiment sparked fierce nostalgia. Students were tasked with designing a contraption to protect a raw egg when dropped from increasing heights. Materials ranged from bubble wrap and cardboard to one student’s “overengineered masterpiece” involving rubber bands, straws, and a parachute.
One Redditor recalled a classmate who wrapped their egg in peanut butter, arguing that the sticky texture would absorb impact. “It worked… until the egg slid out mid-air and splattered on the sidewalk. The teacher laughed so hard she cried.” The lesson? Trial, error, and a little messiness are part of the scientific process.
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3. Dissecting… Anything (But Especially Frogs)
Biology classes divided students into two camps: those who couldn’t wait to dissect specimens and those who gagged at the smell of formaldehyde. A user shared how their teacher turned frog dissection into a detective game. “We had to identify cause of death based on organ health. Turns out my frog had a ‘mystery parasite’—probably added by the teacher for drama. Genius.”
Others praised virtual dissections for inclusivity, but many agreed: “There’s no substitute for holding a real heart or brain. It makes you realize how complex life is.”
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4. The Roller Coaster Physics Project
A physics teacher assigned a roller coaster design challenge using foam tubing, marbles, and hot glue. Teams competed to build the longest ride with loops, drops, and “thrill factor.” One group engineered a corkscrew turn that sent marbles flying across the room. Another incorporated a magnet-powered launch system.
The best part? Calculating velocity and energy conservation. “We failed spectacularly at first,” admitted a Redditor. “But when our marble finally made it through the loop without crashing, it felt like we’d unlocked the secrets of the universe.”
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5. Setting Fire to Money (Safely)
A chemistry experiment involving rubbing alcohol, water, and a dollar bill left students convinced their teacher was a pyromaniac. Here’s the trick: Soak the bill in a water-alcohol mix, light it on fire, and watch the flames die out without burning the money. The alcohol burns faster than the water evaporates, leaving the bill intact.
“The teacher bet someone $20 it wouldn’t burn,” wrote a user. “When the fire went out, the bill was still there—and the teacher handed over the $20. Mind blown.”
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6. The “Murder Mystery” Blood Splatter Lab
Forensic science units turned classrooms into crime scenes. In one activity, students dropped fake blood (corn syrup and red dye) from different heights and angles to analyze splatter patterns. “We had to figure out ‘whodunit’ based on blood evidence,” shared a Redditor. “The teacher even staged a fake ‘break-in’ the night before. Walking into class to see caution tape and chalk outlines? 10/10.”
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7. Extracting Strawberry DNA… In a Ziploc Bag
Biology meets kitchen science in this experiment. Students mashed strawberries in plastic bags with dish soap and salt to break down cell membranes, then filtered the mix and added cold rubbing alcohol to precipitate DNA strands. “Seeing those white, stringy clumps made genetics feel real,” wrote one user. “Plus, we got to eat the leftover strawberry goo. Win-win.”
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Why These Experiments Stick With Us
What makes these experiments unforgettable? Redditors highlighted three key ingredients:
1. Surprise Factor: When outcomes defy expectations (fire that doesn’t burn, foam that erupts on command), students lean in.
2. Hands-On Learning: Touching, building, and even failing creates deeper connections to abstract concepts.
3. Teacher Enthusiasm: A passionate educator can turn a standard lesson into an adventure.
As one user put it: “Our chemistry teacher once said, ‘If you’re not having fun, you’re not doing science right.’ Those experiments made me realize science isn’t just textbooks—it’s about asking, ‘What if?’ and then doing something wild to find out.”
So, to every teacher who’s ever ignited a flame (literally or metaphorically) in their classroom: Thank you. You’re the reason some of us still have a vial of potassium iodide in the garage… just in case.
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