The nuclear fusion mentioned already is of great importance for the formation of the universe. It was only in this way that hydrogen and helium could create the enormous variety of elements that humans could discover little by little.

In the nature nothing is lost, no mass, no elementary charge, nothing at all. The basic measure of all electric charges is positive in protons, negative in electrons. These elementary charges are so unimaginably small that tens of thousands of electrons accumulate on a hard rubber rod, which is rubbed on a suitable cloth.

Charging is called what happens on the rod. It is apparently present everywhere and is transmitted by contact, just as we are accustomed to by electric systems. The accordance of the number of elementary charges with the number of electrons nevertheless shows what is the smallest possible unit, which can be viewed in isolation.

The term 'quantum' comes into play. Whenever you mean a certain part of a certain quantity, you speak of a 'quantum'. And although there are too many electrons around an excess of negative charges, one speaks here of 'deficiency' and only with too many positive ones of 'surplus of charges', the former with the minus, the latter with the plus sign.

When looking at the electron shell, one slowly reaches the limits of Bohr's atomic model. Then electrons are in orbit around the atomic nucleus (atomic shell). The simplest way is the hydrogen atom. Since the distance between shell and core is 10_-11 m, the diameter of the core is about 10_-15 m.

The electron would be as far away from the proton as its diameter is 10,000 times (15 - 11 = number of zeros). Imagine a soccer ball about 20 cm in diameter and you would be 2 km away from it. And this is supposed to be an atom. According to the periodic table of the elements, there are up to more than 100 electrons, distributed to different orbits, and thus to energy levels.

You realize that the imagination power is slowly diminishing. Brief excursion to the car sector: The worst mistake that can happen in the workshop is one that is always present when the vehicle is in customer's hands, but not during test situation. So it seems to disappear when measured or after it is searched.

You will hardly believe it, and there is such a thing in quantum mechanics (quantum physics), which is in search of the really smallest particles, in order to quantify their number perhaps also in the 'normal' physics (exactly limit) can. Because it becomes completely difficult with understanding. Then, really, as in the above workshop example, measured values should have existed only at the time of the measurement.

Again, the question is asked whether an elementary charge is really the smallest occurrence, which is why we have deliberately added the above definition to the fact that we must also be able to look at it in isolation. This is also referred to as the 'subatomic' area, where 'sub' is to be understood as 'subordinate'.

This is supposed to be several hundred particles below the size of an atom, which the Greeks once considered indivisible. No one has actually ever seen an electron in real terms, but only usually light trails after deliberately caused collisions in particle detectors, e.g. at the CERN in Geneva. To explain the formation of molecules we do not consider them necessary here.

So let's stay with the electrons. There are the places where they are now and the path on which they are moving. There are only probabilities for the current location, not exact measurable space coordinates. That belongs to the fact that the electric field of an electron can only be perceived as a whole. There is no amplification in the direction of a possible center.

But we need to know more about them, because it must be clear that atoms first encounter each other with their shells and how far away from the core they are, we can now guess. Somehow, the bonding of atoms to molecules must take place through changes in both atomic shells.

We must therefore be able to assign electrons unambiguously if, as far as we can tell, they change from the shell of one atom to the other. An additional difficulty is that we do not know exactly whether the electron is a wave or a particle. The latter would have a place, of the former we can only measure the spread.