![]() ![]() A pair of electrons in a spin singlet state has S = 0, and a pair in the triplet state has S = 1, with m S = −1, 0, or +1. Capitalized symbols are used: S for the total electronic spin, and m S or M S for the z-axis component. Spin quantum numbers apply also to systems of coupled spins, such as atoms that may contain more than one electron. At a more advanced level where quantum mechanical operators or coupled spins are introduced, s is referred to as the spin quantum number, and m s is described as the spin magnetic quantum number or as the z-component of spin s z. Some authors discourage this usage as it causes confusion. Some introductory chemistry textbooks describe m s as the spin quantum number, and s is not mentioned since its value 1 / 2 is a fixed property of the electron, sometimes using the variable s in place of m s. The phrase spin quantum number was originally used to describe the fourth of a set of quantum numbers (the principal quantum number n, the azimuthal quantum number ℓ, the magnetic quantum number m, and the spin magnetic quantum number m s), which completely describe the quantum state of an electron in an atom. For an electron, m s can be either + + 1 / 2 or − + 1 / 2. It can take values ranging from + s to − s in integer increments. The value of m s is the component of spin angular momentum, in units of the reduced Planck constant ħ, parallel to a given direction (conventionally labelled the z–axis). ![]() The component of the spin along a specified axis is given by the spin magnetic quantum number, conventionally written m s. It is an integer for all bosons, such as photons, and a half-odd-integer for all fermions, such as electrons and protons. It has the same value for all particles of the same type, such as s = 1 / 2 for all electrons. In physics, the spin quantum number is a quantum number (designated s) that describes the intrinsic angular momentum (or spin angular momentum, or simply spin) of an electron or other particle. This quantum number determines the size and energy of the shell containing the electron and has the same integral values as suggested by Bohr.Quantum number parameterizing spin and angular momentum These are denoted by the letters K, L, M, N,…. The quantum number ‘ n ‘ may have any positive integral value from 1 to orīut mainly from 1 to 7 have so far been established. This quantum number denotes the principal shell or main energy level to which an electron belongs. In the same way, each electron in a particular atom is characterized completely by four quantum numbers, the principal, azimuthal, magnetic, and spin quantum numbers which are described below – (a) Principal Quantum Number: They specify the location and energy of an electron in an atom Just as to locate ‘ any person we are required to have information about the town, Mohalia, house number, and name of the person. The number used to identify various states which are available to an electron are termed as ‘quantum numbers‘. The word quantum is used to signify that all the energy levels which are available to an electron are governed by the law of quantum mechanics. Chapter 1st:- Atomic Structure and Periodic Table B.sc 1st year Book () Quantum Numbers
0 Comments
Leave a Reply. |