Science discussion topics (with experiments?) for a 5 year old?

January 9, 2018 8:45 AM

I've been having discussions with my 5 year old about science and he loves it. What are some basic topics I can discuss with him, with simple 'experiments' to go along with them?

We've had a great time talking about solids/liquids/gases, and action/reaction, while doing 'experiments' - warm water in the freezer turns to ice, while ice in your mouth turns to water; a single breath of air through a straw, plus dominos, can make a bell ring across a room.

Can you think of any scientific concepts that we can discuss with simple 'experiments' to go along with them? I'd prefer things that don't require a large amount of setup, but will take any topics and setup. Thanks!

posted by evadery to Science & Nature (25 answers total)

Vinegar + baking soda! You'll get to explain acids and bases and chemical reactions.
posted by foxfirefey at 9:04 AM on January 9, 2018 [2 favorites]

One my Girl Scouts LOVED was when we did our senses badge and took a look at a few different ways our brains try to trick us. I made a huge pitcher of lemonade (nothing fancy, just from the powder, but importantly a BIG batch so it was all the same mixture) and poured it out into a few different containers. I used food coloring--one just normal lemonade, one red, one blue, and one green. Everyone tasted the different colors. The girls all swore that the blue lemonade was the sweetest and most delicious, followed by red, and that the green was too sour. Then I blindfolded them and we did taste tests again--they all tasted exactly the same, obviously.

The girls also really liked when we grew rock candy.

You can do the classic materials density thing with a water bottle and oil, that one's pretty easy.

And on preview I see that firefoxfey has suggested vinegar+baking soda. An excellent suggestion, but if you want to really go nuts with that concept, blow up a balloon or make alka-seltzer rockets.
posted by phunniemee at 9:09 AM on January 9, 2018 [6 favorites]

Rainbows, spectra and colour mixing! We've had lots of fun with a cheap prism, a torch and some coloured filters. Also demonstrating how light mixing is different to paint mixing has been eye-opening even to me (a professional scientist who works with light!)
posted by firesine at 9:11 AM on January 9, 2018

Cartesian Divers!
posted by Dr. Twist at 9:21 AM on January 9, 2018 [1 favorite]

Use your sink and see what floats and what doesn't float and why. (My 4yo's favorite thing to do these days.)
posted by jillithd at 9:22 AM on January 9, 2018 [1 favorite]

If you want fun in vision (my neck of the woods), I'd suggest "how your brain can fool you", particularly the motion aftereffect / waterfall illusion. Here's a good online version, and building a real-world version is fun.
posted by Making You Bored For Science at 9:40 AM on January 9, 2018

se your sink and see what floats and what doesn't float and why.

Oh my gosh, it's the home game of "Will It Float"!

Maybe watering plants with different liquids? Maybe not anything that would outright kill a plant (bleach, etc.), but maybe get three different identical plants and then water one with regular water, one with seltzer, and one with grape juice or something, and then see whether any one grows faster than the others. Hell, a friend of mine did exactly that in fifth grade for the science fair and surprised me when the seltzer one grew faster than regular water.

That of course may lead to a follow-up "okay, what if we watered three more plants with different kinds of soda instead" and you repeat with one plant getting seltzer, and one getting Coke and one Sprite or something.

I also found this link, which has a collection of links to other sites with "simple science experiments for kids". They also rate each experiment's "messiness" for parents as well. They have one about magnetism and cereal which has got me curious already.
posted by EmpressCallipygos at 9:48 AM on January 9, 2018

How about demonstrating how plants absorb water using celery? I remember this from when I was a kid.

All it takes is a few drops of food colouring in some water in a glass or jar, and some celery stalks that have been freshly cut at the bottom.
posted by mandolin conspiracy at 9:53 AM on January 9, 2018 [3 favorites]

You could talk about light - how it travels through space in a straight line forever until it hits something, then gets absorbed, gets reflected, or goes through, depending on what the thing is. Usually some of the light gets absorbed and some gets reflected. When it gets absorbed, it gives energy to the thing absorbing it, heating it up. You can tell when something is absorbing a lot of light because it will have a dark color. Things that are reflecting more light look lighter. Test it out - after a few minutes in bright sunshine, compare how warm dark cloth feels compared to light cloth.

Once your kid has that background information, you can do some experiments with heating cups of water (or keeping them cool.) Put a cup of water on the windowsill in the sunlight and see how it warms up. See if you can come up with ways to make the water get even warmer (paint the cup black, set up aluminum foil around it to reflect more light onto it, etc.) See if you can figure out ways to keep it from heating up as much. (You'll want a little thermometer like this.)

Related to this is the concept of heat. You can explain that things are made of molecules and that heat basically means how much energy the molecules have - how fast they're moving around. Heat can get transferred from one thing to another when molecules from the hot thing bang into molecules of the cooler thing and get them moving faster. (That's conduction.) Or it can get transferred when radiation from one thing hits another thing and is absorbed. (That's the way sunlight heats the water in a cup.)

You can do experiments with speeding up or slowing down heat transfer. Refrigerate or freeze a bottle of water. What can you do to insulate it and keep it colder for longer? What can you do to warm it more quickly? Does it warm up faster in air or in water? (You can show this with an ice cube, too. Does it melt faster set on a plate in a warm room, or dropped into cold water?) Does blowing a fan on the bottle make it warm faster or slower? How does that compare with the way the fan makes you feel when it blows on you?

You can explain that everything is always giving off electromagnetic radiation. If it's a really hot thing (the sun, a fire) it can give off radiation in the wavelengths we can see and call light, but cooler things (people, furniture) give off radiation we can't see and call infrared. That radiation also heats things up when it gets absorbed. Hold aluminum foil in front of your face or hands and see how you can actually feel the radiation being reflected back and warming you slightly. Notice how a fire or stove heats you even if you aren't touching it, because its radiation is hitting you. (You can tell it's not just that the air is getting heated and passing on its heat to you because of the big difference you feel between the part of your body facing the fire and the part facing away.)

Five is a little young to really get all the concepts related to heat and electromagnetic radiation, but probably you could start with some of them and revisit them in more depth over the next few years.
posted by Redstart at 9:53 AM on January 9, 2018 [1 favorite]

My 5-year old is all of the sudden way into direction - so I’m getting him a compass to teach him how it works, and magnetic poles and all that fun stuff.
posted by amro at 9:53 AM on January 9, 2018

- Red cabbage is a great ph indicator. Cook some, add vinegar, and it will brighten up. Add a little sugar to cut the acid and sweet-sour red cabbage is quite tasty.
- In Maine, we had some very cold weather, and demonstrated that boiling water will turn to snow when you throw it in cold air.
- Snow crystals can be examined with a magnifying glass.
- Diet Coke & Mentos. Whatever science is at work is crazy fun.
- I have an app that will tell me when the Intl. Space Station will be visible, and it's very fun to watch it go overhead. Put August 10-12 in your calendar and do outside to watch the Perseid meteor shower, which is basically shooting stars.
- When I was a kid, we had wool carpeting (and pet dinosaurs) and if you scootched across the carpet, you could deliver a nice spark to a sibling.

There are a lot of websites with science fun for kids. Make sure to find some that explain Scientific Method. Start a notebook for recording results. Observe some things that ake time, the way I am cheerfully observing some of the snow going from solid to gas on this sunny day. Even putting a cup f water in a sunny window, and marking the level on an hourly or daily basis, depending on where you live.
posted by theora55 at 10:51 AM on January 9, 2018 [1 favorite]

Dry ice in a sink -- eventually you have a visible carbon dioxide waterfall spilling out onto the floor and countertops, because CO2 is heavier than air.
posted by Fig at 10:56 AM on January 9, 2018 [1 favorite]

Insulation is a fun one. Make two identical blocks of ice, wrap one in a blanket. Most kids assume that because the blanket is "warm", the blanketed block will melt first.

Playing with oobleck (corn starch and water) is another good extension of phases of matter.

Lots of natural-history types of science can be done: we made a map of all of the bushes and trees in our yard; a park or similar would work well too. Or we go for a walk and see how many species of animal we can see, and if we can't identify them, we go home and look them up. We've been keeping track of the phases of the moon lately; kid hadn't noticed that it changes slowly and predictably before.

Theora55 mentioned finding out when ISS is passing overhead: you want Spot The Station for that. This time of year works well in the northern hemisphere because it gets dark before the kid's bedtime.
posted by tchemgrrl at 10:57 AM on January 9, 2018 [1 favorite]

I love this! I nanny a 5 year old boy and he’s very interested in science, too. Last week we had some very cold temps so we did the throw-boiling-water-into-the-air trick on the front porch. We also filled various containers with water and let them freeze outside; it was fun to compare speeds of freezing (we used a donut pan, small plastic containers, plastic cups, etc). We brought the frozen chunks inside and experimented with melting them in a bowl of warm water.

Will be watching this thread!
posted by sucre at 11:26 AM on January 9, 2018 [1 favorite]

Build on the"what floats" activities with not density exploration - pour different liquids into a glass together and see if they mix or separate. Oil, water, syrup, vinegar, etc.
posted by congen at 11:45 AM on January 9, 2018

If you can see the stars, or at least a few bright constellations, try tracking them both over a few night-time hours and also throughout the year. You don't need anything more complicated than identifying that they rotate in one direction or another, and how much they rotate per hour or so. (Why?) Compare with the motion of the sun. And tracking the moon's phases, as mentioned above.

Wayfinding is a good intro to intuiting a lot of geometric concepts. Even basic spatial questions like "What room is directly below your bedroom?" or "What is on the other side of this wall?" can be very good spatial exercises. Get him in on helping you navigate to various places.

Re: radiation, above -- you can feel a hand-shaped cold spot if you're standing near a fire and put your hand out somewhere in front of your body. You can get a similar effect by just using a piece of paper held between your upturned face and a clear night sky -- you will feel a significant difference in heat, since empty space is near absolute zero but the piece of paper is at least a few hundred degrees hotter. You can also get Mylar blankets for about $1/each.

If you cook, there's a ridiculous amount of accessible science in that. One easy one is defrosting methods: the fastest standard way to defrost is in a bowl of running water, vs. still water (at various temperatures) vs. air circulation. Leavening agents in bread. Osmosis: dumping salt or sugar onto porous stuff will often result in lots of water coming out. Water makes up most of the food we eat: you can check before/after a heated dry with a kitchen scale. Pressure vs. temperature: air-filled water bottles collapse in the fridge. See: all of Alton Brown.

You can get a microscope with 1000X magnification -- enough to see your own larger cells, as well as some mesoscale structure of stuff like eraser shavings, plant veins, paper tissues, graphite, table salt, etc. -- for $50-$100 on Amazon. It will gross you out, and it's well worth it.

I should note that a lot of the explanations for the above can get quite involved, but I don't think that's really the point. Even just noticing half of this stuff -- being able to chew on it over a period of months and years -- is immensely valuable.

Have fun!
posted by miniraptor at 12:03 PM on January 9, 2018 [2 favorites]

Colour changing milk from Steve Spangler Science is a simple but fun experiment. Steve Spangler has a ton of different experiments on his website.
posted by Lay Off The Books at 1:14 PM on January 9, 2018

I made bath bombs with my 4-year old niece and her older brother. We talked about chemical reactions when we were making them and also when they used them in the bath (a huge hit!). I've also made slime with them, cooked with them, and I have a butterfly enclosure and milkweed ready for Spring so we can hopefully observe the Monarch Butterfly life cycle.
posted by quince at 2:49 PM on January 9, 2018 [2 favorites]

When my daughter was about six, we did a little experiment where we buried plastic cups up to the brim in different parts of the yard and checked them nightly to see what kinds of insects had fallen in and gotten trapped. We counted and categorized them and then released them. It was pretty cool for her and we were all kind of amazed at the variety of bugs around us all the time.
posted by Pater Aletheias at 3:22 PM on January 9, 2018 [3 favorites]

Probably best to save for when they're a little older, I've done this with 8-10 year olds, but hydrochloric acid (sold as muriatic acid, as a concrete cleaner and pool Ph balancer) is a lot of fun. The difference between older (solid copper) pennies and modern (copper covered zinc) pennies is fun to illustrate, and using aluminum foil and hydrochloric acid to get hydrogen (use a wine bottle, tie a balloon over the top of the wine bottle) is pretty cool.

The hydrogen demonstration both lets you experiment with density (it wants to rise!), and if you tie the balloon to a 10' length of PVC and wave it over a candle or lit blowtorch gives a convincing "boom" and flame.
posted by straw at 3:34 PM on January 9, 2018

Oh yeah, quince's mention of the monarch butterfly life cycle reminded me how much my daughter and I learned from raising caterpillars. (Lots of caterpillars! There were times we had 20 different types in containers in our kitchen.) There's a lot to learn besides just the basics of the life cycle. For instance, it's a great opportunity to talk about predation and ways to avoid it (camouflage, spines and warning coloration, being active only at night, etc.) Did you know that there are way more moth caterpillars than butterfly caterpillars out there? Do you know the difference between pupa, cocoon, and chrysalis? Did you know there are wingless moths? Did you know female caterpillars tend to grow larger than males?

You can also try putting out sugar bait for moths.
posted by Redstart at 5:43 PM on January 9, 2018

And if you talk about heat, you can talk about how some materials conduct heat better than others. Have your kid go around the house touching things and noticing which ones feel cold. Or put some things out in the sun or next to a heater and see which ones get warmest. Metal feels colder to the touch than wood because it conducts heat better, so your fingers lose heat quickly when they touch it.
posted by Redstart at 5:49 PM on January 9, 2018 [1 favorite]

In 2nd grade science class we had microscopes shared at our desks, and a few other things. The teacher said to pretend we were an alien scientist, and we had picked up a leaf for the first time to study. What observations can we make about it?
He passed around the leaf, and a paper where each of us was to add one thing we observed about the leaf.
No one put down that it was green.
No one put down the weight.
This made a big impression on me about paying attention to the basics.
posted by Sophont at 7:14 PM on January 9, 2018

My kids (6, 8 and 10) were gifted a MEL Science subscription this xmas. The first one hasn't arrived yet, but we are psyched to see what we get!
posted by wwartorff at 7:23 PM on January 9, 2018

Fill a ziplock bag with water and then pierce it with pencils and it won't leak. I don't know why -- you'll have to google that.

Another one is the egg being sucked into a bottle when you light a match inside. Something about atmospheric pressure. Again, you'll need to google it because I don't remember the actual lesson.
posted by AppleTurnover at 8:21 PM on January 9, 2018