For many years, Luigi Galvani and Alessandro Volta had an academic dispute about electricity. Luckily for us today, they based their respectful exchange of arguments on experimental evidence. As a result, both of them could make important contributions to science. Volta, for ...

Chirality is important in physics, maths, biology and especially in chemistry. Although many students manage easily to memorize the definition, it usually takes more than words to comprehend this property and its consequences in 3 dimensions.

Typical catalysis experiments involve fire or rather complex biochemical reactions with enzymes. If you are looking for a safe way to teach the concept hands-on, something just at the right speed to be easily observed, a couple of raisins or rice corns ...

Adding salt to water increases its density and allows some objects – like apple seeds – to float which would sink in pure water. This is a faster and cheaper classroom alternative to the often cited experiments of making an egg float ...

With a bit of food coloring or a tea bag in hot and cold water you can quickly demonstrate the kinetic theory of temperature. Why not turn the tables and ask your students to prove (or disprove) the theory to you? Let ...

One simple experiment that simultaneously demonstrates two examples of corrosion: A rather obvious one, forming a green patina (the same that makes old copper roofs and monuments look so nice), and a less visible one that apparently 'cleans' the surface.

The fast rusting of steel wool is a safe and clear example of an exothermic reaction that can be done with regular household items. If you want to contrast endothermic and exothermic reactions, you might want half of the class to do ...

Surfactants (e.g. detergents) tend to build a monomolecular film on a water surface. While a monomolecular layer is hard to observe with the naked eye, in this experiment it can be 'seen' pushing aside pepper on the water surface.

Capillary forces in a wick can transfer oil to a flame or a liquid from one vessel to another. But what makes a good wick? Let your students find out in a small competition.

A simple yet very effective setup to study capillary forces: Let your students discover for themselves what makes the water rise between two glass slides.

Surface tension can hold a surprising volume of water on a coin. If the surface tension is reduced, e.g. by adding a surfactant, the water spills over at a far lower volume.

Discussing the implications of this well-known experiment can be of great help to 'grasp' the idea of a dipole moment in water molecules. Ask your students to explain in a drawing why water is attracted by electrical charges. This allows them ...

Common water is among the most interesting materials on Earth. One of its many extraordinary features is the unusual dependency of its density on temperature, as seen in this simple yet beautiful experiment.

In regions where the temperature drops below zero, salt is often used to 'melt' ice and snow on the streets (see also 'Salt and Ice'). Many people do not know that while the ice indeed melts, it is not getting warmer but ...

In cold regions of the world, salt is used to free streets and pedestrian walks from ice. But how does salt melt ice? In fact, it doesn't – it just reduces the freezing while not affecting the melting, thus shifting the equilibrium ...

This little game is based on a famous psychology experiment. Researchers demonstrated with it that humans often hold a confirmation bias: We naturally tend to seek evidence that confirms our current believes, rather than to look for evidence that falsifies theories. Karl ...

There are many elaborated experiments that show the force of air pressure with pumps and other advanced equipment. But just a few questions about an everyday experience – the inflating of a balloon – can make clear why air exerts a ...

Spectrometers are usually closed boxes. This spectrometer, in contrast, is literally open, and allows with simple means and basic math to measure for instance the spectral bands of a fluorescent light bulb. Some students have achieved remarkably accurate results in less than ...

Dimitri Mendeleev noted that there was something regular in the list of chemical elements, with some groups of elements sharing similar characteristics. When he finally discovered the underlying pattern, he was able to correctly predict the existence, and even some properties, of ...

Marie and Pierre Curie observed radioactive decay as a glow in their darkened laboratory. It is NOT recommended to repeat this experiment with your students! Instead, let your students explore the law of radioactive decay with a bag of dice. This ...