Kids at-home science experiments (of the less tame variety)
My 5-year-old loves doing “science experiments” at home with me and her older siblings, but it seems that the online lists of experiments we’re choosing from are truncated to leave off all but the least dangerous activities. This makes sense for a lot of low-parental-involvement contexts, but I’m going to be directing and deeply involved in these experiments. And I want fire. Smoke. Sparks. I want to make these experiments feel adventurous so the kids get really excited about whatever we’re learning. Baking soda and vinegar volcanoes and elephant toothpaste just don’t cut it.
What experiments can you recommend using only relatively common household materials? Chemicals, candles, electricity, a stovetop, etc. (Assume that the experimenters will all be taking standard precautions, wearing PPE, and generally using the experiments as both an opportunity to learn about science and about the safety measures that go with science experimentation.)
Or if you know of any websites listing these more spectacular home science experiments, please share those as well.
Bonus if the experiments involve multiple possible outcomes that the kid can use pen and paper and elementary math to predict in advance.
I used to do science experiments with scouts when my kids were younger. The favorite was always the calcium carbide balloons. Order a small jar of calcium carbide, which will come in small pieces. Put a piece inside a balloon, add a little water, and quickly tie the balloon shut.
The water and calcium carbide create an exothermic reaction that produces acetylene gas. The kids can hear the hissing of the reaction, feel the warmth of it through the balloon, and see the balloon inflate. Then, holding the balloon stem with tongs, hold the balloon over a candle at arms length to create a small fireball as the acetylene gas ignites.
When I was 8th grade
I builtmy dad built me a giant tesla coil for a science fair. It was pretty fun to show off how it could light up florescent bulbs a foot away and make everyone's hair stand up. It did knock out VHF signals for a block or so around the school when we flipped it on though.I imagine the copper and equipment for something that big would be a bit pricey these days but something smaller scale like that might still be fun.
Vandegraaf generators are cheaper and can be a lot of fun. I made one in 7th grade and it was the hit of the school science fair. Kids were lined up waiting to get shocked.
Magnets and electricity in general are pretty neat. Most of it requires math beyond what a 5 year old will understand, but there's a bunch of easy things that can be done.
So... A potato railgun? I'll let myself out.
By the way, a regular potato cannon is probably plenty exciting for a 5 year old, and can teach stuff ( see smarter everyday video, which might also give you other fun sciency experiment to try )
Dang, was this before people carried super computers in their pockets?
Well...um...yes, would have been about 1990. Unless you discharge through the phone you won't have a problem.
You can get a similar effect by holding long fluorescent light bulbs under High Tension Power lines.
Where are you holding the light bulbs glows.
If you have a safe OUTDOOR place (preferably with concrete underneath), you can use a sparkler to light some thermite on top of sand and demonstrate just how hot it gets by the sand melting and demonstrate what an extremely exothermic reaction looks like
In that vein, exploding small hydrogen balloons can be great fun. Start very small and make sure to use a long stick.
Hydrolysis is pretty easy. Use the hydrogen for small bomb and use the oxygen to boost flames on a candle.
Oh, completely unrelated idea. If you have a fireplace or fire pit (or just a big concrete patio and a wet day) , you can buy salts to add to a fire that changes the color. Epson salt makes white, boric acid (borax) will do a purple/green flame, potassium salt will make a blue/purple...
It would be easiest to do with a good torch, but you could probably just wrap a little salt in paper and light that on fire.
Back in the day, we used to put sections of green outdoor water hose inside pieces of copper pipe to make exciting colors in campfires. Pinks, blues, greens. It was always different. I wonder how many exotic chemicals we inhaled.....
Lithium can explode when added to water - do with that what you will.
Depending on the level of danger you're going for and the amount of space you have, you could construct a plexiglass 'blast wall' ala mythbuster and add enough lithium to a (plastic) breaker filled with water to cause it to explode. This also works with glass but that's even more dangerous and, although I survived and it was cool, should probably not be recommended.
Wear eye protection! I had a science teacher do this experiment and a small shard of the exploding lithium went into my eye. It was not fun.
Dry ice can be purchased fairly affordably, and you can do some neat stuff with it.You can use it to freeze a soap bubble so you can pick it up. That's a neat demonstration on how much colder it is than water ice - - that's a neat transfer into the phases of matter and how the same material can be a solid, liquid or a gas.
The simplest explosion is putting some in a plastic bottle or Pringle can and then sealing it(watch from a window inside). You can use that to explain that gas is less dense and takes up more space than a solid, and you can use the dry ice in general to explain sublimation.
Early videos from the YouTube channel The King of Random had a lot of great experiments like this. I'm talking very early, like 10ish years ago.
The original channel owner, Grant Thompson, passed away at some point, and in my opinion the channel had already gone to crap before then. But the early videos with Grant and even later with Nate are really good.
I know you asked for common household materials but for anyone looking for something ready made I would recommend Mel Science. They provide all the materials (equipment, chemicals), PPE, and instruction cards. I believe they have an app too but we've never used it. The instruction cards provide info on the level of difficulty and danger for each experiment. For a lot of the experiments, they provide enough material to do a couple of times if not more (and some materials are easy enough to replace).
I will say it's not exactly cheap, but it's a monthly subscription and I feel like you get a good bang for your buck. We subscribed for about a year for the chemistry set when our kids were 7 and 5 (under strict supervision) during COVID. They're now 11 and 9 and still fond of doing the experiments from time to time.
Hmm, metal powders + flames is always a good one. If you can get your hands on some low explosives or other pyrotechnics, these can be quite the joy. I imagine simply mixing the right metals into black powder will already get you colorful flames, plus "how do metals manage to color the flames" is a neat way to jump into a lot of cool chemistry and physics.
I could also see calcium carbide being a lot of flaming fun. It's basically gravel that dissolves into sludge and acetylene. If ever you need a source of a flammable gas, this one is quite convenient. Chuck some into a plastic bottle, along with some water, close the bottle up and place it close to a source of ignition, now wait for the bang.
If you've got a benchtop power supply and a glass jar, there's endless opportunities for electrolysis experiments. Just electrolysing salt water is a source of hydrogen (gas, flammable), chlorine (gas, corrosive, ventilation is paramount) and sodium hydroxide solution (liquid, corrosive). Oh, and if your electrodes are cheap metal, you'll probably end up with sludge in the water. There's probably a lot cooler stuff you can do than just a bunch of colorless gasses and liquids. Maybe you can turn copper into copper oxide (by consuming a copper electrode) to make more energetic copper thermite? Careful with that stuff though, iron-alum thermite is tame in comparison. While we're at energetic metals, "flames that can't be extinguished by water" is always a good one.
Also, very tame, but get a microscope and look at everything.
Or, if you're the Primitive Technology minded sort, check if you can't order a pound or two of iron ore and turn it into metallic iron. That project would bring me endless joy, I think. Or ask your nearest machining shop if they've got a hefty, flat piece if scrap steel that you could use as an anvil for amateur smithing. Need a source of heat, of course, and tongs and a hammer.
I vaguely recall Mr Wizard back in the day balancing safety with entertainment, might be worth checking out a book from the library if they still have them or some old videos. (Someone's probably got a list of every experiment he ever did.)
Caveat, they could in fact be boring now and I'm just old
My daughter was just talking about how at school, they put baking soda in a balloon, vinegar in a plastic water bottle. Put the balloon on the top of the bottle and then tip the baking soda in to inflate the balloon.
Since it produces co2, another experiment I was thinking about would be to put candles of different heights in a bucket or empty aquarium, put a bowl of vinegar in the bottom. Light the candles, then add baking soda. As the co2 fills the container, it will extinguish the candles one by one. You can also out the vinegar/baking soda in a tall glass or vase, let it go for a bit, then "pour" the gas (not the liquid!) over a candle to put it out.
You can make hydrogen gas by putting aluminum foil in muriatic acid (pool chemical) which is just hydrochloric acid. It's a very exothermic reaction. I have done it (dangerously) with a glass soda bottle, putting a balloon on top to inflate with hydrogen. If you do it right, the balloon will float, and it will make a burst if flame if you pop it with a candle on a stick.
It can be hard to handle because it gets so hot, and sometimes it kicks acid up into the balloon. That is bad because it spatters when you ignite the balloon and it makes it too heavy to float. If I were doing it again, I'd probably want to make some apparatus to make it safer.
Be careful doing balloons with air and hydrogen in them. It is an explosive mixture (vs the h2 balloon, which only burns when it contacts the oxygen outside the balloon as it pops. The o2+h2 balloon can burst ear drums and break windows if done indoors.
Coffee creamer will burn because it's a very fine powder (lots of surface area). One way to do it is to get short piece of PVC and fit some latex surgical tubing over one end to make a long straw. Fill the tube with creamer, the blow it out in a cloud over a candle. The tubing is long to keep your face away from the fire.
You can get long lengths of latex surgical tubing at the hardware store and make an arbitrarily large slingshot between two trees or posts.
You can get old corroded pennies and make them shiny in lemon juice.
You can make rock candy / grow sugar crystals by making a super saturated sugar solution (try saying that three times fast) and hanging a string in it. More details.. I think you can do this with salt crystals as well.
You can make a potato battery with a potato and a copper and zinc electrode. It works with oranges/lemons as well, I think.
If you peel an orange and squeeze the peel so the skin is facing outward, the liquid it sprays out is flammable.
Cornstarch and water makes a non-Newtonian fluid, sometimes called oobleck.
You can put oil and water in a jar and shake them up, then see them settle out. Then add an egg white to it and see that they stay mixed. Plus you made mayonnaise.
If you put different colored food coloring in clear glasses and fill one with hot water and one with cold water, then put a card over the cold water, invert it, put it over the top of the other glass, and pull the card out, you'll see the hot water rise and the cold water sink. You can switch them (hot water on top) and they won't mix as much.
You can put heavy whipping cream in a small jar and shake it, and it will turn into butter. Add a little salt to taste and put it on bread.
I also have this book (sadly unused) but I bought it because it had good reviews.
I wonder if using a bit of garden hose and an S bend from the bottle into the balloon will help trap everything heavier than the hydrogen gas at the bottom of the S bend, so only the gas makes it into the balloon?
Yup, that's exactly the kind of thing I was thinking of. You'd need a good way to make a connection to the bottle. If I were doing a lot of these experiments, I'd probably bite the bullet and buy some glassware/stoppers/tubing and a Bunsen burner so I could make my own glass lab apparatus.
For OP, 5 years old is a bit young to include them in the making, but I used to help the chemistry teacher in my high school make lab apparatus and it was a lot of fun.
Depending on your budget, you could try making a setup to anodize niobium. It can be a combination science + art project because they can make jewelry or metal sculptures with the anodized wires/sheets of metal. The more science-y end is to observe what color happens at what voltages and create a chart (and also learn a bit about safety when working with electronics, and some of the chemistry + E&M background), the more art-y end is to then use that data to make something the colors they want. I've heard recommendations for Rio Grande as a supplier, and if I ever get around to doing this myself that's what I'll buy.
I did this in high school chem lab and it was a lot of fun, and I want to do it now to actually make wires to use in chainmaille jewelry. I think with adult supervision it's appropriate for kids too!
Not sure if this is the kind of thing you are looking for, but in that vein:
Check out kid science kits. They contain detailed instructions and some experiments that you wouldn't be able to do otherwise, since they use some chemicals that you probably won't just buy in a grocery store
This one from National Geographic seems great, though I don't know what specific experiments are there and what's their danger level:
https://www.amazon.com/NATIONAL-GEOGRAPHIC-Amazing-Chemistry-Set/dp/B09LRHSXW9?th=1&psc=1
And since those kits are made specifically for kids, they're usually specifically focused on experiments that look cool and exciting (although yeah, it usually still includes elephant toothpaste and other classics, but there are often others which do involve actual fire and sparkles and stuff)