What are quantum numbers? And how many are there?

Answer 1

Each electron has a set of four numbers, called quantum numbers, that specify it completely; no two electrons in the same atom can have the same four. That's a more precise statement of the Pauli exclusion principle.

Primary quantum number, which is given the symbol n,n tells you which of the "main" energy levels you're in.

The second quantum number is known as l. A value of l=0 corresponds to s, l=1 is p, l=2 is d, and so forth.

The third is magnetic quantum number m. l, along with n and the third quantum number, m, is responsible for determining the shape of an electron's probability cloud.

The fourth quantum number, s, does indeed pertain to an electron's spin. s only has two possible values+1/2 or-1/2.s= +1/2 means "spin up" and s= -1/2 means "spin down."

Within the level given by a particular n, l can take on only integer values from 0 to n-1.So when n is 1, l can only be 0, and that's why the first row has only s states. Then when n=2, l can be either 0 or 1, and that gives you s and p. Given a particular l, m is entitled to be any integer from minus l up to l. For example, when l=1, m can be -1, 0, or 1; those are your three p states. For a given l, there are 2l+1 different values of m..

Answer 2

Quantum Numbers Definition

Answer 3

The quantum numbers are the numbers denoting the different states of electrons or in general any particle, the quantum states as they call it.
The number of q.n.s (quantum numbers) depends on the particle and the situation in which it is. for example an electron inside the atom will have 4 quantum numbers, if it is free then it don't have any quantum number associated with it. The existence of quantum number in a system just indicates that the energy in the system is discrete. As it is in case of an atom. But when particle is free, it's energy is not quantised.(Remember this is not against the quantisation of energy since a free particle is an imaginary concept and it doesn't exist.)

Answer 4

A quantum number describes the energies of electrons in atoms. Each quantum number specifies the value of a conserved quantity in the dynamics of the quantum system. It is any of a set of real numbers assigned to a physical system that individually characterize the properties and collectively specify the state of a particle or of the system.

Answer 5

Quantum mechanics dictates that bound particles live in states that aren't described by continuous variables, but by discrete variables which correspond to solutions of the differential equations that govern them.

A particle in orbit (a spherical potential), for example, has 3 quantum numbers

(1) a primary (n) which corresponds to the energy and the solution of radial differential equation.
(2) Angular momentum (l)
(3) and z-component of angular momentum (ml) which correspond to solutions of the angular differential equation.

In addition to the quantum numbers describing its orbit, a particle can have many other intrinsic quantum numbers.

Spin describes an intrinsic angular momentum (and magnetic moment) in addition to the orbital (l)

Baryon number, color, flavor, lepton number, isospin, hypercharge, charge conjugation, parity, and many other such quantum numbers also help describe the particle and govern its interactions with other particles.

Answer 6

quantum numbers are the numbers which gives us the information about the electrons maoving around the atom
ther are three types of quantum numbers :
they are :
1) principle quantum number(n)
2) azimuthal quantum number(l)
3) spin quantum number(+/-)

Answer 7

4 quantum numbers:

1. principal quantum number(n): n- 1,2,3,4,5,6, or k,l,m,n,o,p,.

tells about the radius and energy of principal shell.

2. azimuthal quantum no. (l) : l= 0(n=1).l=0,1(n=2), l=0,1,2(n=3) and so on .

tells about no. of subshells present

3. magnetic quantum no(m) : m=-l to +l , eg: for l=1, m= +1,0 , -1

tell us about the no. of orbitals present in a subshell , orbitals of same subshell have same energy called degenerate orbitals

4. spin quantum no. : +1/2 or -1/2

Answer 8

Quantum numbers are helpful in knowing the energy,shape, position ,number of orbitals of an electron .These are of 4 types.They are principle (gives energy level),azimuthal(number of subshell),magnetic(orientation),spin(whether positive or negative spin)

Answer 9

Quantum numbers is a set of four numbers which tell us about the position and nature of electrons.
They are
1)principal
2)azimuthal
3)magnetic
4)spin

Answer 10

Quantum nos. are those which decide the basically orientation, direction and position of an electrons.
There are basically 4 types of quantum no.s present namely principle Qno. represented by n, second is denoted by l, third is magnetic Qno. denoted by m, fourth is spin Qno. denoted by s which gives the direction of electrons either clockwise or anticlockwise