Quantum numbers are trajectories located in the interior of atoms or describe the movement of electrons. Atoms are surrounded by electrons that are distributed regularly in orbitals.

The distribution of electrons can be neat because it is regulated based on quantum numbers or descriptions of electron positions. The numbers in this quantum mechanical atomic model can explain the properties of atoms clearly,

An analogy to the mechanical atomic model is that the atom is described as a solar system where the sun is the atomic nucleus which includes protons and neutrons. Meanwhile, electrons are analogous to the planets that surround them with their respective energy levels.

**What are Quantum Numbers**

Reporting from *Ruangguru.com *, quantum numbers describe the position of electrons in a quantum mechanical model of the atom. Around the atom, the largest electrons are arranged according to their energy levels. This energy level describes the locations where electrons are distributed from quantum numbers.

The quantum number that is easy to find is the quantum number of the final electron. A set of quantum numbers consists of four numbers including azimuth quantum, principal quantum, spin quantum and magnetic quantum.

**Types of Quantum Numbers**

The description of electron positions or quantum values is divided into several types, namely as follows:

### 1. Principal Quantum Numbers

This number is an electron shell where the value n=1 indicates the deepest electron shell in an atom. Of course, it corresponds to the lowest energy state or ground state of an electron. A larger principal quantum value indicates a larger distance between the electron and the nucleus.

A larger principal quantum number implies a larger atomic size. The principal quantum can be an integer with a positive value. For example, in cesium (Cs), the outermost valence electron is in a shell with energy level 6 so that electrons in cesium can have n values from 1-6.

### 2. Azimuth or Angular Momentum (ℓ)

The azimuthal or angular quantum value describes the subshell and gives the angular magnitude of the orbital momentum. In chemistry and spectroscopy, ℓ = 0 is known as an s orbital, ℓ = 1 is known as a p orbital, s orbital, ℓ = 1 is known as a d orbital and =f is called an f orbital.

The value of ℓ ranges from 0 to n – 1 because the first p orbital (ℓ = 1) appears in the second electron shell (n = 2), the first d orbital (ℓ = 2) usually appears in the third electron shell (n = 3) and so on. In chemistry, quantum numbers are important for determining the shape of atomic orbitals and considerably influence chemical bonding and viewing angles.

### 3. Magnetic Quantum Value

Magnetic quantum numbers indicate energy levels in subshells and express orbital projections in three-dimensional space. It could be analogous to the atomic shell being a multi-story dormitory and the subshell being a floor containing a number of rooms.

The magnetic quantum number (m) projects the distribution of electrons in the rooms on each floor. Magnetic quantum in orbital space shows the orientation of electrons.

The magnetic quantum value depends on the azimuthal quantum number. The value of mℓ ranges from – to ℓ with integer steps in between which the s subshell (ℓ = 0) contains one orbital and therefore the mℓ of electrons in the s subshell will always be 0.

The p subshell (ℓ = 1) contains three orbitals so that the mℓ of electrons in the p subshell is 1.0 or 1. The d subshell (ℓ = 2) contains 5 orbitals with the values m 2, 1, 0, 1, and 2. Quantum value mb usually associated with orbital orientation.

### 4. Spin Quantum Value

The spin quantum value states the direction of rotation or rotation around an electron axis. The direction of this rotation can be clockwise. This number does not depend on other numbers.

The spin quantum value is indicated by ±1/2 or -1/2. What is included in the positive spin quantum is the direction of the electron’s spin upwards (spin up). A negative number means that the direction of the electron’s spin is downwards.

The spin quantum number describes the magnetic properties of an electron. When opposite spins are combined, they cancel each other out so there is no net magnetic field.