Who invented chemical reactions

chemistry

A chemist at work. He works in a fume cupboard in the event of toxic fumes.

Chemistry is a natural science and also a school subject. The word comes from the ancient Egyptian language and means "black earth". Chemistry is about what substances there are and what their properties are. Another task for chemists is to find new substances that have special properties.

Important substances are, for example, iron, hydrogen and carbon. Chemistry also studies transformations that create new substances, so-called chemical reactions. A chemical reaction is, for example, the burning of a candle, which can be recognized by the flame: When burned, the candle wax produces gases such as carbon dioxide and water vapor. There is also a chemical reaction when baking cakes: New substances are created from the liquid dough and you then have the solid cake. An explosion is also a chemical reaction.

What are atoms

A model of a water molecule

The most important thing for chemists are the atoms. It is the small particles that make up everything around us, including us humans. However, atoms cannot really be seen with the naked eye or even with the best microscopes because they are so small. Ten million atoms next to each other would be about a millimeter wide.

When atoms stick together permanently, you have molecules. Most substances are made up of molecules. The chemists write the most famous molecule as H2O on - it's the molecule of water. The notation means that the water molecule consists of two hydrogen atoms H and one oxygen atom O.

But a chemist has to know the atoms. He needs to know how they behave when they meet and how they stick together. But it is not easy to understand what you cannot see. That is why children only have chemistry as a subject in higher school grades.

What do you do in chemistry as a school subject?

The big X on this bottle of toilet cleaner is a hazard symbol. It indicates that the content has an irritating effect, e.g. that the skin can be reddened.

Chemistry is usually only available as a school subject in Germany from the 7th grade or even later. That depends on the state in which the school is located. In chemistry as a school subject, experiments are among other things. Special devices and chemical substances selected by the chemistry teacher are used.

However, students are not allowed to do all of the experiments they want to perform. Because that can be very dangerous. The chemistry teacher is familiar with it because he studied chemistry at the university. Therefore, he explains to the students exactly what they should do and what they have to pay attention to for safety.

Chemistry also plays an important role in the household. Because many cleaning agents are not entirely harmless. In chemistry lessons, the students learn how to handle such dangerous substances.

What do chemists do?

Test tubes to examine small amounts of liquids

Chemists have researched this for many years: Which atoms and molecules ensure that a certain substance has certain properties? By now the most important things are probably known. However, chemists still have important roles to play.

Chemists invent new substances: They know what a molecule has to look like in order for a substance to be firm, soft or rubber-like. You also know why fabrics are transparent or opaque. That is why they can specifically manufacture such substances. While in the past primarily crude oil was used to manufacture such plastics, chemists today tend to use natural substances that a farmer can manufacture.

Chemists also examine the environment for substances. They answer these questions, for example: Is the water clean? Can you eat that or does it contain poisons? Since you cannot always see, taste or smell poisons, this must be checked to be on the safe side. Chemists know the properties of all substances, including poisons. With the help of certain chemical reactions and devices, they can detect the toxins.

The chemists in the Middle Ages, the alchemists, tried to make gold from cheap materials like lead. But this is not a chemical reaction and it is not even possible. To do this you would have to change the atoms, that would be incredibly expensive.