electronic configuration of Cr3+

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.
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3. In the ground state, the electrons occupying the orbitals singly will have their spin parallel.
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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