N The same electron is an electron shell, and the electrons move in almost the same spatial range, so it is called principal quantum number. When n= 1, 2, 3, 4, 5, 6, 7, the symbols of the electron layer are K, L, M, N, O, P, Q respectively. When the principal quantum number increases, the average distance between the electron and the nucleus increases correspondingly, and the energy of the electron increases. For example, the energy of electrons in a hydrogen atom is completely determined by principal quantum number n: E =- 13.6 (EV)/n 2.
(2) angular quantum number L
Angular quantum number L determines the shape of atomic orbit, and together with principal quantum number determines the energy levels of electrons in multi-electron atoms. The motion of electrons around the nucleus not only has certain energy, but also has certain angular momentum m, which is closely related to the shape of atomic orbit. For example, when M=0, that is, l=0, it shows that the motion of electrons in atoms has nothing to do with angles, that is, the orbits of atomic orbits are spherically symmetric; For example, when l= 1, its atomic orbit is dumbbell-shaped; If l=2, it is petal-shaped distribution.
For a given value of n, quantum mechanics proves that L can only be a positive integer less than n: L = 0, 1, 2, 3...(n- 1).
(3) magnetic quantum number m
The magnetic quantum number m determines the direction of atomic orbits in space. Atomic orbits of a certain shape can extend in different directions in space, thus obtaining several atomic orbits with different spatial orientations. This is based on the phenomenon that the linear spectrum can still split in the magnetic field, showing a slight energy difference.
The magnetic quantum number can take values: m = 0, +/- 1,+/-2 ...+/-l.
(4) spin quantum number ms
Directly from Schr? The fourth quantum number, the spin quantum number ms, cannot be obtained from the Schrodinger equation, but was introduced according to the later theoretical and experimental requirements. Accurate observation of atomic spectrum in the presence of strong magnetic field shows that most spectral lines are actually composed of two spectral lines that are very close together. This is because electrons move outside the nucleus, and they can also take two motion states with the same value and opposite directions, which are usually represented by ↑ and ↓.
Give you two more detailed explanations:
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Simply put:
Extranuclear electron number
1 Floor: 2
Second floor: 2 8
3 2 8 8
4 2 8 18 8
5 2 8 18 18 8
6 2 8 18 32 18 8
The above figures are the largest.
The outermost electrons of this layer of elements gradually increase, and the other layers are the largest.
(only IA~VIIA family, not all elements of b family meet)
Electron configuration of rare gas accords with the maximum number.
This is the simplest statement, and the simple statement is definitely incomplete.
Want to fully understand, or look at my previous information.