I’m sure we’ve all done the fun project of putting vinager into a bowl of baking soda and watching the resulting joy. Does anyone know of any more of these little safe and fun science type things to do at home with the kids? Things that don’t require a trip to a chemical factory or a dozen safety permits?
Thanks
Google “egg in bottle”.
By the way, I developed a variation on the vinegar/baking soda experiment. You take one of those “one-zip” plastic bags – the type with a sliding “zipper” on it – and put baking soda into it. Have an assistant pour in some vinegar, after which you close the bag as quickly as possible. If you have the right amount of ingredients, the bag will inflate and eventually pop. You’ll have to experiment to find the right amount of vinegar and baking soda.
Well if you don’t mind not moving away from the vinegar and baking power you can experiment with how temperature influence reaction speed.
By adjusting the temp of each component you can basically make 4 experiments
Lt = Low Temp
N = Room Temp
Vinegar = N Baking Soda = N
Vinegar = N Baking Soda = Lt
Vinegar = Lt Baking Soda = N
Vinegar = Lt Baking Soda = Lt
Get a few tall clear glasses and do a comparison.
Cornstarch + water = non-Newtonian fluid! It feels liquid when you touch it with a small amount of force, but solid when you touch it more forcefully.
Raw egg + vinegar + time = awesome
Put a raw egg, still in it’s shell, in a cup of vinegar. Wait a few days (IIRC, it takes about 3, but you can check the egg whenever).
The shell gets eaten off and you get to see the yolk/white inside the membrane, it’s like a little egg balloon. Make sure to check it though, since the membrane will get eaten away shortly after the hard shell does.
Although 35 mm film canisters may be hard to come by these days.
Also, The Thousand Yard Model
I have wanted to do this since I first read about it 20 years ago. It’s a
“model” of the solar system where both the size of the planets and the
distances between them are on the same scale. The sun is a bowling ball,
and 26 yards away is the Earth as a peppercorn! Pluto is about 1000 yards
from the sun.
It’s a great outdoor and daytime exercise in astronomy. The write-up is
here:
http://www.noao.edu/education/peppercorn/pcmain.html
And here’s a Wikipedia page on Solar System Models:
coffee filter
water soluble (“washable”) marker in black, green, orange colors (black works best)
cup of water.
Cut coffee filter into strips and color a circular spot on the bottom of one of the colors.
Put the strip so the end with the dot is in a small amount of water and let it wick up the strip.
As the water wicks up the strip the different pigments will separate.
For a delicious baking soda experiment, make hokey pokey!
Another simple, yet fun one is cornstarch and water. Slowly add just enough water so that it forms a mixture that is somewhere between a liquid and solid. When you poke it and pick it up it will feel like a solid but the moment you let it rest in your hands it reverts to a liquid like status. This was a cheap but fun thing to play with in elementary school.
You can make your own pH indicator with red cabbage. When I googled it up, I found other kitchen experiments.
I may have to try the rainbow density column. Pity I don’t have any kids to blame that on.
When I was a kid I liked to put a chicken leg bone in vinegar for a few days, after which it could be tied in a knot.
I also liked to grow potato plants by sticking toothpicks in a potato to suspend the bottom part in a jar of water. You can watch as roots grow in the water and the top sprouts into a plant.
You can very simply teach about temperature and pressure by blowing up a balloon and putting it in the freezer for a few minutes and observing how it shrinks and holding it over a heat source to see it grow.
“Martian lander experiment”
Take glass jars. Fill with sand. To some add salt, others add baking soda, to one add yeast. Tell the kids to devise experiments to tell which of the jars contain life.
The red cabbage pH experiments have been mentioned.
You can also do the pigment experiments with flower and leaves…mash up flowers in alcohol, and dip filter paper in. The different pigments in the flower migrate at different speeds so you’ll get zones of different colors.
Then there’s good old crystal making. Get a bunch of household chemicals–salt, baking soda, sugar, epsom salt, etc, make supersaturated solutions, and dip a string in them, and let the crystals form over a week. Another interesting way is to take construction paper, wet it with the solution, and let it dry, it will form crystal paper.
>Fill a fairly flat plate with water.
>> Set a short candle in the middle.
>>>Light the candle.
>>>>Cover lit candle with a drinking glass.
Results: The water from outside the glass will be sucked into the drinking glass.
Oh, the chicken leg reminds me. Take one chicken leg and soak in vinegar. Take another and heat it for a long time, like near a furnace. The vinegar dissolves the minerals in the bones, leaving it like rubber. The baking denatures the protein in the bone, leaving it brittle and crumbly. Demonstrates that both components are needed for bone strength.
Oh, another one. Prove CO2 is heavier than air. Take two paper grocery bags, hang them from two ends of a long dowel, and hang the dowel so the bags are perfectly balanced, like a scale. Then make CO2 gas via baking soda/vinegar, and pour the invisible CO2 into one of the bags. That bag will sink because CO2 is heavy.
You can burn steel wool but doesn’t burn well in air. You can make O2 from hydrogen peroxide and manganese dioxide, the black stuff inside a battery. Capture the O2, light steel wool on fire, then place it in the oxygen. Sparkly!
Another extremely easy demonstration is the Mobius strip.
If you take a strip of paper (about one inch wide by 11 inches long will work) and tape the ends together, you get a regular paper ring, one inch wide and 11 inches around. It has an inside and an outside, as can be demonstrated by drawing a line with a pen around each surface. If you cut the ring in two, you get two rings, each one-half inch wide and 11 inches around. All very normal and expected.
Now take an identical strip of paper, and turn one end 180 degrees (i.e., so that the top becomes the bottom), then tape the ends together. You now have a Mobius strip that has only one surface. To demonstrate this, start at any point on the strip, start drawing a line around it, and see what happens.
Then cut the ring in two as before, and see what happens.
Then, if you’re careful enough, cut the result in two again, and see what happens.
Do your baking soda and vinegar experiment in a tall pitcher or similar, then, after the fizzing stops, you’ll have a pitcher full of carbon dioxide. Light a candle and pour the CO2 out over the flame - it looks like you’re pouring nothing (make sure you stop before you get to the sludgy liquid vinegar stuff at the bottom!) but the flame will be smothered as the oxygen is pushed away by the denser, heavier gas.
These are all great! Thanks. I’m especially looking for showy things. She’s only 4, so I don’t know that she’ll have a lot of patience for some of the longer experiments. But I am going to print this thread (and it’s links) to use in a couple of years.
Keep 'em coming.
Diet Coke & Mentos are fun!
Remember those old, glass milk bottles with the wide mouth? If you’re lucky enough to have access to one of those you could heat it up in boiling water, carefully remove it from the water bath, then set a peeled, boiled egg on the top. As it cools (thereby changing the air pressure)…zoop!…the boiled egg is sucked into the bottle.