The central equation of quantum theory agrees with both the wave nature of particles and Heisenberg`s uncertainty principle. Schrödinger`s equation provides wave functions Ψ of the position of the electron with respect to the permitted energies In chemistry and quantum physics, quantum numbers describe the values of quantities conserved in the dynamics of a quantum system. The principal quantum number (n) describes the size of the orbital. Orbitals where n = 2 are greater than those where n = 1. Since they have opposite electric charges, electrons are attracted to the nucleus of the atom. The energy must therefore be absorbed to excite an electron from an orbital in which the electron is close to the nucleus (n = 1) in an orbital in which it is further away from the nucleus (n = 2). The principal quantum number thus indirectly describes the energy of an orbital. The azimuth quantum number (l) describes the subshells and thus the shape of the corresponding atomic orbital: the principal quantum number is limited to a positive integer. The third rule, which limits the allowed combinations of quantum numbers n, l and m, has an important consequence.
It forces the number of sublayers in a shell to be equal to the principal quantum number of the shell. For example, the shell n = 3 contains three sublayers: the 3s, 3p and 3d orbitals. There is only one orbital in the shell n = 1 because there is only one way to align a sphere in space. The only permissible combination of quantum numbers for which n = 1 is as follows. The angular quantum number (l) describes the shape of the orbital. The orbitals have shapes that can be described as spherical (l = 0), polar (l = 1) or clover (l = 2). They can even take more complex forms as the value of the angular quantum number increases. The special value of ml determines the orientation of the distribution of an electron in space. If l is zero, ml can only be zero, so there is only one possible orientation. If l is equal to 1, there are three possible orientations for the distribution of an electron.
If l is equal to 2, there are five possible orientations of electron distribution. This is increasingly true for other values of l, but we do not need to consider higher values of l here. Each ml value designates a specific orbital. So there is only one orbital if l is zero, three orbitals if l is equal to 1, five orbitals if l is equal to 2, and so on. The quantum number ml has no effect on the energy of an electron unless the electrons are exposed to a magnetic field – hence its name. The number of orbitals in a shell is the square of the principal quantum number: 12 = 1, 22 = 4, 32 = 9. There is one orbital in an s subshell (l = 0), three orbitals in a p sublayer (l = 1) and five orbitals in a d sublayer (l = 2). The number of orbitals in a subshell is therefore 2(l) + 1. Four quantum numbers can be used to fully describe all the properties of a given electron belonging to an atom, namely: In 1913, Danish scientist Niels Bohr proposed a reason why the atomic spectrum of hydrogen looked like this. He proposed that the electron in a hydrogen atom could not have random energy, but only certain fixed energy values indicated by the number n (the same n in the equation above and now called the quantum number).
Quantities with certain specific values are said to be quantified. Bohr proposed that the energy of the electron was quantized into hydrogen because it was in a certain orbit. Since the energies of the electron can only have certain values, energy changes can only have certain values (similar to a staircase: stairs are not only set to certain heights, but the height between the steps is fixed). Finally, Bohr proposed that the energy of the light emitted by electrified hydrogen gas is equal to the energy difference of the energy states of the electron: since each orbital of this subshell now contains an electron, the next electron added to the subshell must have the opposite spin quantum number, thus filling one of the 2p orbitals. The Bohr model was a one-dimensional model that used a quantum number to describe the distribution of electrons in the atom. The only information that mattered was the magnitude of the orbit, which was described by the n-quantum number. Schrödinger`s model allowed the electron to occupy three-dimensional space. So it took three coordinates or three quantum numbers to describe the orbitals in which electrons can be found. Although there is no pattern in the first four letters (s, p, d, f), the letters are alphabetic from this point (g, h, etc.). Some of the allowed combinations of quantum numbers n and l are shown in the figure below. Electron shell: a group of atomic orbitals with the same principal quantum number n (n = 1 ⇒ first layer) Electronic subshell: a group of atomic orbitals with the same principal quantum number n and the azimuth quantum number l To simplify the details of the four different quantum numbers related to atomic physics, A tabular column with their names, Symbols, meanings and possible values is given below. The 4 quantum numbers are the address of an electron.
The set of numbers used to describe the position and energy of the electron in an atom are called quantum numbers. There are four quantum numbers, namely major, azimuthal, magnetic, and spin quantum numbers. Bohr`s ideas were useful, but were only applied to the hydrogen atom. However, later researchers generalized Bohr`s ideas into a new theory called quantum mechanics, which explains the behavior of electrons as if they were acting like a wave rather than a particle. Quantum mechanics predicts two important things: quantized energies for electrons in all atoms (not just hydrogen) and an organization of electrons in atoms. Electrons are no longer considered randomly distributed around a nucleus or confined to certain orbits (Bohr was wrong in this regard). Instead, electrons are collected in groups and subgroups that explain a lot about the chemical behavior of the atom.
