electronic configuration of Cr3+

Asked by adityalearn28 | 28th Sep, 2010, 10:37: PM

Expert Answer:

Cr has electronic configuration [Ar]4s1 3d5
 
Cr3+ has [Ar]4s1 3d2.
 
means, electron will go from 'd' orbital because its easy to get out electron from outer shell.
 
we sometimes deviate from aufbau in those elements having high atomic number because of very less energy gap between the successive orbitals.
 
HUNDS RULE:
 
When several orbitals of equal energy are available, electrons enter singly with parallel spins
  
RULES OF ELECTRONIC CONFIGURATION
 
HUND'S RULE OF MAXIMUM MULTIPLICITY
 
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


 

 

 


Answered by  | 28th Sep, 2010, 11:44: PM

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