Login

Hunds rule of maximum multiplicity notes. Tell me and reply with answr

Dear Student,

Hund's rule of maximum multiplicity states that if two or more orbitals of same energy are available, electrons first fill the available orbitals singly and then proceeds to fill them in pairs.

Examples:

Carbon: Its electronic configuration is 1s2 2s2 and 2p2

In, p there are three orbitals of equal energies. So, the electrons will first fill them singly. So, two orbitals have one electron each instead of one orbital having 2 electrons.

Fluorine: Its electronic configuration is 1s2 2s2 and 2p5

In, p there are three orbitals of equal energies. So, the electrons will first fill them singly. So, three orbitals get filled by one electron and then they are filled in pairs. So, two orbitals have paired electrons and one orbital has a singly filled orbital.
Regards,
 

  • 1
View Full Answer
1) Rule            : The rule states that for a given electron configuration, the lowest energy term is the one with the greatest value of spin multiplicity. This implies that if two or more orbitals of equal energy are available, electrons will occupy them singly before filling them in pairs.

2) Explaination :First of all maximum multiplicity means high spin state. High spin state defined as 2s+1 where “s” is spin of total no of unpaired electrons for e.g if there is no unpaired electrons it is in Singlet state because 2*0+1=1

And if there there is two unpaired electrons it is in Triplet state 2*1+1=3 like that So higher the multiplicity lower the energy of a state means higher the stability. So that why lower energy states filled first i.e, state with maximum multiplicity filled first. that’s why we call it as law of maximum multiplicity .

I hope this will help you.
Regards !



 
  • 1
According to Hund's rule of maximum multiplicity:
1. The electrons tend to avoid being in the same orbital.Thus as the electrons are successively added, a maximum number of electrons will try occupy orbitals singly.
 
 .
  2. When all the orbitals are singly occupied only then the pairing of electrons commences.
  .  
  3. In the ground state, the electrons occupying the orbitals singly will have their spin parallel.
.  
Hund's rule indicates that the electronic arrangement   is more stable than   .
EXPLANATION
  
N (Z = 7) :
CORRECT AND STABLE ELECTRONIC CONFIGURATION = 1s2, 2s2, 2px1, 2py1, 2pz1
WRONG AND UNSTABLE ELECTRONIC CONFIGURATION = 1s2, 2s2, 2px2, 2py1, 2pz0
 
 
  • 0
What are you looking for?