Electricity, electricity, electric current, electron charge - these words everyone knows.
So what is electricity like?it is formed and transmitted? It is not easy to give answers to these questions. To do this, you need to familiarize yourself with a significant range of phenomena called electrical. First consider the origin of the word "electricity".
Even before our era, scientists from ancient Greecefound that after rubbing objects from amber light bodies are attracted to them. Amber in Greek is an "electron"; it is from this word that the name "electric" occurs.
In the second half of the 16th century, the English scientistGilbert discovered that not only amber possesses the property of attracting light bodies. This property is also acquired by rubbing many substances, for example, resin, glass. This phenomenon is called electrification. A substance acquiring such a property in friction was called electrified.
Electrification of bodies scientists explained the appearance of electricity on the body or electric charge.
To make the body electrified, not necessarilyto rub it; you can, for example, touch it with any pre-electrified object. Thus, experience shows that electrified bodies repel or attract. Proceeding from this, we came to the conclusion that there is a different electric charge. These are opposite charges.
Some of these charges were conventionally calledpositive, and others - negative. Observation of the interaction of electrified bodies made it possible to establish that the charges of the same name will be repulsed, and unlike charges will be attracted.
The question of what iselectric charge, interested scientists for a long time. At first, it was assumed that electrical phenomena are caused by an electrical fluid that has no weight. Some scientists assumed that each body has two electrical fluids: positive and negative, with the excess of one forming positive electrification of the body, and the surplus of the other - 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 electrical fluid that is contained in a certain amount in each uncharged body. Surplus of it in the body forms positive electrification, and the disadvantage - negative. However, gradually the analysis of new experimental facts led to abandon the hypothesis of an electrical fluid.
So, it was discovered that electricity hasatomic structure, i.e. it can be divided into component parts, each of which is a so-called elementary electric charge. This conclusion made it possible, on the one hand, to study the passage of electricity through solutions of salts and acids, and then to study electricity in gases. And, finally, experience has shown that elementary electrical charges transfer the smallest particles of matter.
Experiments conducted in the late 19th century by Englishphysicist Thomson, made it possible to open a separate particle of matter with the lowest electrical charge, and subsequently it was possible to measure its value.
Thus, the smallest particle of matter that has an elementary negative charge is called an electron.
The electric charge of an electron is one of the most important inseparable properties of an electron.
Its mass is m = 9,1˖10⁻²⁸ g.
The charge of the electron is e = -4.8˖10⁻¹⁰ units.
Electron is one of the particles that enter intothe composition of each substance. Substances consist of atoms, which contain a positively charged core and electrons that move around it. The negative charge of an electron is completely identical in any substance, however their number and distribution near the nucleus is different. When the atom is in a neutral state, the positive charge of the nucleus equals the sum of the negative charges of all the electrons that rotate around it.
It happens that the atom loses electrons; in this casethe positive charge of the nucleus becomes larger than the sum of the charges of the remaining electrons, then the entire atom becomes positively charged. When the body is charged negatively, it means that the electrons in it are in excess.
The motion of electrons determines the redistribution of electric charges in substances, positive and negative electrification of bodies and other phenomena.
