Electricity, electricity, electric current, electron charge - everyone knows these words.
So what is electricity, how is it generated and transmitted? Answering these questions is not easy. To do this, you need to familiarize yourself with a significant range of phenomena called electrical. Let us first consider the origin of the word "electricity".
Even before our era, scientists of ancient Greece found that after rubbing objects from amber, light bodies are attracted to them. Amber in Greek - "electron"; it is from this word that the name "electric" comes from.
In the second half of the 16th century, the English scientist Hilbert discovered that not only amber has the property of attracting light bodies. Many substances, such as resin, glass, also acquire this property during friction. This phenomenon is called electrification. A substance acquiring such a property by friction was called electrified.
Scientists attributed the electrification of bodies to the appearance of electricity on the body or to an electric charge.
For the body to become electrified, it is not necessary to rub it; for example, you can touch it with any previously electrified object. Thus, experience shows that electrified bodies repel or attract. Based on this, we came to the conclusion that there is a different type of electric charge. These are charges opposite to each other.
Some of these charges were conventionally called positive, while others were negative. Observation of how electrified bodies interact has made it possible to establish that like charges will repel, and opposite ones will attract.
The question of what constitutes an electric charge has been of interest to scientists for a long time. At first it was assumed that electrical phenomena are caused by an electric fluid without weight. Some scientists suggested that each body has two electric fluids: positive and negative, and an excess of one forms a positive electrification of the body, and an excess of the other forms a negative. If they are present in equal amounts, then the action of both liquids destroys each other. In this case, the body becomes uncharged. Other scientists believed that there is only one electric fluid, which is contained in a certain amount in each uncharged body. An excess of it in the body forms a positive electrification, and a deficiency forms a negative. However, gradually the analysis of new experimental facts forced to abandon the hypothesis of electric fluid.
So, it was discovered that electricity has an atomic structure, i.e. it can be divided into component parts, each of which represents a so-called elementary electric charge. This conclusion allowed us to draw, on the one hand, a study of the passage of electricity through solutions of salts and acids, and then a study of electricity in gases. And finally, experience has shown that elementary electric charges carry the smallest particles of matter.
The experiments conducted at the end of the 19th century by the English physicist Thomson made it possible to discover a separate particle of a substance that has the smallest electric charge, and later it was possible to measure its value.
Thus, the smallest particle of a substance that has an elementary negative charge is called an electron.
The electric charge of an electron is one of its most important inseparable properties.
Its mass m = 9.1ห10โปยฒโธ g.
The electron charge e = - 4.8 410โปยนโฐ units.
An electron is one of the particles that make up each substance. Substances consist of atoms, which include a positively charged nucleus and electrons that move around it. The negative charge of the electron is exactly the same in any substance, but their number and distribution around the nucleus are different. When an atom is in a neutral state, the positive charge of the nucleus is equal to the sum of the negative charges of all the electrons that revolve around it.
It happens that an atom loses electrons; in this case, the positive charge of the nucleus becomes greater than the sum of the charges of the remaining electrons, then the whole atom will become positively charged. When the body is negatively charged, it means that the electrons in it are in excess.
The movement of electrons determines the redistribution of electric charges in substances, the positive and negative electrification of bodies, and other phenomena.