What are Quantum Numbers in Simple Words

Do you Know !!

What are Quantum Numbers?

In simple words, quantum numbers are certain numbers which are used to locate electrons in an atom.

or

In other words, we can say that quantum numbers are addresses of electrons. They are of four types out of which three are obtained by mathematical solution of the Schrödinger wave equation.    

4 Quantum Numbers

(i)   Principal Quantum Number (n):

It is obtained by mathematical solution of r-part of the Schrödinger wave equation.

Its values are:

n = 1, 2, 3, ………..,∞

  • It represents the shells or orbits or energy levels

When n = 1

It means 1st shell or K-shell

n = 2 

It means 2nd shell or L-shell

n = 3 

It means 3rd shell or M-shell

  • It also indicates energy. Higher is the value of “n” more is the energy.
  • It also indicates the distance of the electron from the nucleus. Higher is the value of “n” away is the electron from the nucleus.
  • The numbers of electrons in a shell are calculated by it as 2n2.

(ii)  Azimuthal Quantum Number (ℓ):

It is obtained by the mathematical solution of θ-part of the Schrödinger wave equation. It is also called a secondary quantum number. Its values are:

   ℓ = 0, 1, 2, 3, ……….., n-1

  • It represents the subshells or  energy sub-levels

When ℓ = 0    It means s-sub shell (spherical shaped) 

s stands for sharp  

ℓ = 1

It means p-subshell (dumbbell-shaped)

p  stands for principal

 ℓ = 2

 It means d-sub shell

(sausage-shaped) 

d stands for diffused

ℓ = 3

It means f-subshell                 

f  stands for fundamental

  • It also indicates energy up to some extent. Higher is the value of “ℓ” more is the energy.
  • It also represents the shapes of orbitals.
  • The number of orbitals in a sub-shell can be calculated by it.
  • Number of orbitals in a sub-shell = 2 ℓ + 1
  • The number of electrons in a sub-shell can be calculated by it.

Number of electrons in a sub-shell = 2(2 ℓ + 1)

Azimuthal Quantum Number

(iii) Magnetic Quantum Number (m):

It is obtained by mathematical solution of Ø-part of Schrödinger wave equation. Its values are:

Values of     m = – ℓ , …,0 ,……..,+ ℓ

The number of values of      m  = 2 ℓ + 1

  • It represents orbitals and their orientations

e.g ( i)   if     ℓ = 1    It means p-subshell and for p-subshell,

Values of m  = 2ℓ + 1 = 2 x 1 +1 = 3

These values of m  = -1,0,+1

It means that the p-subshell has three orbitals with three different orientations.

  orbitals            px         py         pz

  m                    +1        -1         0

e.g(ii)  if  ℓ  = 2   It means d-sub shell

and for d-subshell, number of values of m  = 2ℓ + 1 = 2 x 2 +1 = 5

these values of m are = -2, -1, 0, +1, +2

It means that d-subshell has five orbitals with five different orientations.

orbitals  

 dxy   dyz   dz2   dxz       dx2-y2

m     -2     -1    0      +1        +2

Magnetic Quantum Number ( in Urdu / Hindi)

Spin Quantum Number (ms):             

It describes the spin of electrons. Its values are

   ms = + ½ , – ½

When  ms = – ½   electron shows clockwise spin (↑)       

ms = + ½   electron shows anti-clockwise spin (↓)    


Recommended video :

4 Quantum Numbers Explained ( in Urdu / Hindi )

Also, Watch !!!

Difference between Shell ,Subshell and Orbital

Rating: 1 out of 5.

Check out free notes !!

-> Class 10 Chemistry Full book pdf

-> Class 11 Chemistry Full book pdf

-> Class 12 Chemistry Full book pdf

For joining best Chemistry Coaching

4 thoughts on “What are Quantum Numbers in Simple Words”

  1. Excellent site. Plenty of helpful information here.
    I am sending it to several pals ans additionally sharing in delicious.
    And certainly, thanks to your effort!

  2. I was just searching for this information for
    a while. After six hours of continuous Googleing, finally I got
    it in your web site. I wonder what’s the lack of Google strategy that do not rank this kind
    of informative web sites in top of the list. Generally the top websites are full of garbage.

    Also visit my web site SynoGut Side Effects

  3. Fantastic post but I was wondering if you could write a litte more on this
    topic? I’d be very grateful if you could elaborate a little bit further.
    Kudos!

Leave a Reply

%d bloggers like this: