10 simple home experiments that explain physics and chemistry

10 home experiments that explain physics and chemistry

There are effects in nature that catch us off guard, or tests of known products that surprise us. Most can be highlighted in simple experiments that we can do at home without complications. Discover with us ten curious experiments ...

1. How much sugar does Coca Cola have?

It's a classic since someone recorded it and uploaded it to YouTube. By now we all know (right?) That soft drinks have a lot of sugar. And that sugar does not suit our body , some call it the nicotine of the 21st century. A can of Coca Cola (33cc) has about 35 grams of sugar no less: like five! Sachets of sugar for coffee.

Can of Coca-Cola

The experiment is simple: you pour a can of Coca Cola into a saucepan, and bring the liquid to the boiling point. The water evaporates, and in the end there is a paste that is all that sugar ... The mere sight of this rest takes away from many the desire to continue consuming.

2. The profits of Coca Cola

Since we have started with the popular soft drink, let's also say that it has its benefits. Do you have any rusty metal parts? Well, put it in a glass with Coca Cola. As it is acidic (partly to compensate for the taste of the sugar it contains) it will attack the rust. After a few hours you will see how your screw, nut or the piece comes out clean .

Rusty nails and screws

Clean, and sparkling. If that piece was chrome or stainless, you will be surprised by the shine that Coca Cola leaves on it. This is because the acid it carries is phosphoric, it reacts with chromium and leaves a protective layer of chromium phosphate. Try cleaning an old fender , or parts of a custom motorcycle, with a cloth and Coca Cola: brilliant!

3. The invisibility cloak

Harry Potter has some magical providers and his invisibility cloak is an impossible thing ... sure? For something not to be visible, it is enough that the light that is reflected from the object does not reach our eyes. And there are ways for that to happen, without magic.

Glass with oil

Find a small glass and a large glass in the kitchen, and add olive oil between the two. Now place an object, or put a finger, in the small glass, and look from outside ... it is not there! Magic? No, science. The light that reaches the object and is reflected, strikes at such an angle on the glass of the first glass, the oil and the second glass, that it cannot pass (due to their refractive index) . And if the light does not pass, we do not see what is inside. Apparently, we only see the glass of the glasses and the oil between them.

4. Walk on water

This in addition to a magician we have seen many insects do ... how do they not sink? It is due to the surface tension that all liquids have. Liquids take the shape of the containers that contain them: their molecules are held together, but with less force than in a solid. But the molecules of the last layer (surface) are "held" by their neighbors only. In that area there is more attraction and the liquid does not "break".

Insect leftover water

This surface tension allows insects to walk on water. Pour a thin paper on a surface of water, and place a needle or clip on it : when you remove the paper, they will "float". If you drop them even carefully, they may break the tension and sink.

5. Non-Newtonian fluid

Let's continue in the kitchen: that of the "non-Newtonian fluid" will sound strange to you but it is understood immediately. It is a fluid that does not always behave in the same way before external agents. If you move it slowly, it is very thin, very liquid. If you move it fast, it seems that it becomes more viscous, thicker.

Look for cornstarch or fine corn flour: we are not going to make pancakes or a sponge cake (although you can take advantage). Mix it with water little by little until you get a ball of pasta . You already have your non-Newtonian fluid: if you hold it in your hand, you will see how it falls apart. But try punching him ... surprise! It looks like a rubber ball.

Non-Newtonian corn mass

This property, with synthetic materials, is used to make bumpers and safety pillows . Some "lying guards" have even been patented: if the car arrives slowly, they sink and do not cause a pothole. If the car comes fast, they stiffen and jerk to slow the driver down.

6. Cooler ice

While we're in the kitchen, let's look at some other experiment. As you know, water freezes at zero degrees centigrade. When you buy a bag of ice and put it in a bucket to chill soda, that ice is zero degrees. Is it possible to cool it more?


Well yes, and surely you know the trick if you have a chemist friend and you do barbecues at his house. Add salt to the ice . The dissolution of the salt with the water that is releasing the ice as it melts, is an endothermic reaction. That is, it absorbs energy: it cools. And also, salty water freezes at a lower temperature than pure water: that cube that was previously at 0ºC, could reach 20º below zero if you mix the ice and salt well. The next time you make salted fish or meat in the oven (very rich and very healthy), don't throw that salt away when you remove it. It will serve for the summer parties ...

7. Another ice, water and salt

Even those who know that salt and ice trick will be amazed by this new experiment. Pour cold water into a glass, and drop an ice cube. Take a textile thread (sewing for example) and drop it on the cube. If you pull it, logically, nothing surprising will happen . Still.

Glass with water and ice

Now add a little salt on top of the ice cube, where the thread rests. Wait a few moments, and pull the string: it has stuck to the ice cube and it comes out of the glass. What has happened is that where you put salt, it has dissolved in the water in the ice cube. As in the previous experiment, this lowers the temperature but also "melts" the ice (which, since it is salty, needs much more cold to freeze). As the wire has been wet with water, that water freezes , "soldering" the wire to the cube.

8. Colorful and unbreakable soap bubbles

Let's take advantage of the surface tension again, that which allows insects to walk on water. A soap bubble is a perfect example of this: water alone is not capable of holding its molecules together, forming bubbles. But if it has dissolved soap, it is possible because the tension is enough to contain the air it contains ... and there is the pomp.

Soap bubbles

But we can "strengthen" the solution: in addition to soap, add glycerin to the water. Glycerin increases the surface tension more and you will make more resistant bubbles, they may even bounce off the ground like balloons if you mix well. Once you are there, try adding some sugar: it will increase the brightness and color of the bubbles.

9. Atmospheric pressure

This is a classic test for us to understand that the air around us also has a certain pressure . A glass of water is filled, leaving one finger unfilled. Take a CD case or a similar plastic, which covers the glass, and cover it. Holding the lid, you turn the glass over, and when it is upright, you release the lid.

Inverted glass with water covered

No, you won't get wet. The water wants to dislodge the glass due to the effect of gravity. But if it did, the air chamber above it (the finger that we left when filling it) would decrease its pressure. At the same time, atmospheric pressure acts on the plastic lid , pressing it on the glass still in an inverted position. Of course, if it does not fit well and bubbles leak, prepare the mop because it will break the balance and the lid will fall ... and the water.

10. Light candle remotely

Combustion is a phenomenon between gases . When we see a solid burn, it is because at the point of the flame it is going directly to gas. Or more usually to liquid and this to gas. A good example of this is a candle: the wick burns because the heat liquefies the wax and it evaporates, combines with the oxygen in the air, and burns.

You do not believe it? Well, light a candle, and when it takes a few minutes, try to put it out suddenly, without it getting cold. A lot of smoke will come out of the wick: bring a flame (match or lighter) to that smoke, even if it is far from the candle or wick. Yes, it lights up again : that smoke was melted and evaporated wax. I said, combustion is a matter of gases.

Burning candles