Hasty match
Why does one of the matches escape to its own path and the other floats in place? Try it yourself, but DON'T TASTE!
SUPPLIES:
A flat container, e.g. a deep plate or a pie dish
Water
Matches
Liquid dishwashing detergent
GUIDE:
Pour water into a flat container.
Take a match and dip its end in dish soap.
Put the match in the water and observe its trajectory.
Take another match and put it in water without dishwashing liquid.
SCIENCE:
The dishwashing liquid breaks the surface tension of the water and then the particles of the water surface can move quickly in the liquid and push the match to the edges of the plate. Surface tension is caused by the attraction forces between the molecules of the liquid, cohesion, which in turn is caused by the internal forces of the molecules.
Density tower
How to make a density tower? Try it yourself!
SUPPLIES:
A tall dish
Syrup
Cooking oil
Water
(Food coloring)
Small objects of different weights that fit in the container
GUIDE:
Pour about 1/3 of the syrup into the bottom of the dish.
Pour approx. 1/3 of the water (dyed with food colouring) in the middle.
Finally, pour approx. 1/3 cooking oil on top.
Observe how the different liquids are arranged in the container.
Drop small objects into the container.
In the video, e.g. the number lottery cube stops in the syrup layer, a small piece of pencil remains on the surface of the oil layer and the marble ball sinks to the bottom.
SCIENCE:
In this trick, the density of different liquids and objects is observed. When a layer of water is poured on top of the oil layer, the water sinks below the oil, because the water is denser than the oil. Syrup is denser than water or oil, so it sinks to the bottom of the container. When different objects are dropped into the container, they remain floating in a place corresponding to their density. It can be generalized that if the density of the object is lower than the density of the surrounding medium, the buoyancy is a greater force than the weight and for this reason different objects remain floating in different layers.
Spice star
How to do science and art with surface tension? Try it yourself, but DON'T TASTE! At the same time, you can perceive the power of the dishwashing liquid.
SUPPLIES:
Plate
Water
Oregano or other similar coarse spice
Liquid dishwashing detergent
GUIDE:
Pour water on a plate.
Sprinkle oregano or other coarse seasoning on the plate so that the surface is covered.
Pour some dishwashing liquid on top.
Observe and admire the unique shapes!
SCIENCE:
Dishwashing detergent reduces the surface tension of water. When dishwashing liquid is added to the water, the spice powder literally splashes around the edges of the plate, forming different patterns. The spice powder moves on top of the tearing surface tension film.
Lava lamp
A bubbling lava lamp doesn't illuminate, but it dazzles with its magnificence, don't you think? Try it yourself!
SUPPLIES:
Deep or other rimmed container (for mess)
A narrow glass, jar or bottle
Water
Cooking oil
Effervescent tablet
Food coloring
GUIDE:
Fill approx. 1/2 of the glass (or jar/bottle) with water that has been colored with a couple of drops of food coloring.
Fill the rest of the glass with oil.
Wait for the oil to separate into its own layer.
Add a couple of drops of food coloring.
I drop in an effervescent tablet and I calmly observe what is happening in the container.
SCIENCE:
Water and fat-soluble oil do not mix, but the denser of these substances, i.e. water sinks to the bottom of the container. Food coloring only dissolves in water, and therefore the oil will not be colored. Bubbling "lava" is formed when the effervescent tablet reacts with water and carbon dioxide gas is formed. Carbon dioxide bubbles attach to water molecules and transport them through the oil layer.
Upward climbing water
How do you make the water rise up in the glass? Try it yourself!
SUPPLIES:
Thermal candle
Plate
Water
Glass (or test tube, as in the video)
Matches
(Dye)
GUIDE:
Pour approx. 1 cm of water on the plate. (If you color the water, you can see more clearly what is happening.)
Light the heat candle and place it on the plate. Do not pour too much water on the plate, so that the candle does not start to float.
Put the glass upside down on top of the candle on a plate and observe the water level in the glass. (If you use colored water, you can see the effect better.)
SCIENCE:
Air plays a big role in this science trick. Inside the glass is air, which consists mainly of oxygen and nitrogen. Oxygen is needed for the combustion process. Therefore, the amount of oxygen in the air decreases when the candle burns. The air also heats up when the candle burns, and this causes the air to expand and partially escape from the edges of the glass by bubbling. Eventually, the candle goes out because the amount of oxygen decreases. After that, the air cools and its volume tends to decrease. The pressure in the glass drops and the outside air pressure pushes the water into the glass so high that the pressure differences equalize.
A non-Newtonian fluid
How can matter be both solid and liquid in a way? Try it yourself if you don't believe it!
SUPPLIES:
Potato flour
Water
Plate
GUIDE:
Mix approx. 2/3 of potato flour and 1/3 of water on a plate, i.e. 2 dl of potato flour and 1 dl of water.
Observe the composition of the slime by rolling a ball of it in your hands. Add water/potato flour if necessary.
Enjoy!
SCIENCE:
This non-Newtonian fluid, i.e. potato flour-water-slime, does not obey Isaac Newton's traditional understanding of how fluids should behave. Co. the viscosity, i.e. the thickness, of the slime does not change when the temperature changes, but due to the effect of an external force.
Bubbles
Bubbles like Heureka...
Note Do not try this yourself!
SCIENCE:
Carbon dioxide ice that comes into contact with warm water, i.e. dry ice, begins to gasify strongly. The transformation of a solid substance directly into a gas is called sublimation. Carbon dioxide gas is invisible, but the extremely cold temperature of carbon dioxide ice (-78.5 °C) causes the water vapor in the air to turn into visible ice crystals, i.e. to become frosted. The carbon dioxide gas escaping from the bottle can be used to make soap bubbles when the end of the hose is dipped in the dishwashing detergent solution. Detergent removes the surface tension of water, so the film formed by water molecules can withstand stretching. The carbon dioxide gas coming from the hose remains inside the water film, and this is how a bubble is formed. Carbon dioxide is a gas heavier than air, which is why the bubbles fall to the table and do not remain floating.