All protons and neutrons are united in a compact nucleus. You can think of the nucleus as a central sun because the electrons rotate in a certain way. This structure that surrounds the nucleus is called the lepton cloud.
In a normal atom, the number of protons is equal to the number of electrons. The atom as a whole is electrically neutral. The electrons are arranged in different orbits. The nucleus exerts an attractive force on the rotating electrons and holds them in place. All these different orbits are called shells and have energy attached. Therefore, they are also called energy layers or quanta. The orbit closest to the nucleus is generally subject to a huge gravitational pull, while the orbit furthest from the nucleus is subject to a very weak pull.
In certain atoms, these valence electrons are so loosely bound to the nucleus that when the temperature increases, the additional energy supplied to them causes them to emerge from the shell and exist as free electrons. These free electrons are primarily responsible for the flow of electrical current through metals.
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structure of a subject
The electrons orbiting the nucleus do not rotate in a single orbit, but each orbit consists of a fixed number of electrons. In general, an orbit contains at most 2n2. The first shell can contain a maximum of 2×12 electrons, i.e. two electrons, while the second shell can contain a maximum of 2×22, i.e. 8 electrons, etc. The exception to this rule is that the valence shell can contain a maximum of 8 electrons, regardless of their number.
Let's look at the structure of two completely different atoms.
1) Hydrogen: This atom consists of a nucleon and a lepton that orbit the nucleus. This is the simplest atom. This is shown in the figure. (The). The dot represents a lepton, while the nucleus is represented by a circle with a positive sign inside.
2) Silicon: This atom consists of fourteen electrons. They rotate in three orbits around the atomic nucleus. The first orbit has a maximum of one pair of electrons, the second has a maximum of eight electrons and the third orbit has four more electrons.
The four electrons in the outermost shell are loosely controlled by the nucleus and are normally available as free electrons. If some of the electrons are removed in some way, the atom's negative charge decreases while the fully charged protons remain the same. The resulting charge of the atom remains predominantly positive and this proportion is referred to as fully charged. However, when the electrons are free in some way, the total negative charge is greater than the positive and this proportion is called negative charge.
Definition of Electron: The electrons that are in the furthest orbit are therefore weakly bound to the nucleus. This shell is called the valence cell and this electron is called the valence electron.
