Transition metals and many of their compounds show paramagnetic behaviour where there are unpaired electron or electrons. The magnetic moment arises from the spin and orbital motions in ions or molecule. Magnetic moment of n unpaired electrons is given as
`mu=sqrt(n(n+2))` Bohr magneton
Magnetic moment increases as the number of unpaired electrons increases.
Q. There are three unpaired electrons in `[Co(H_2O)_6]^(2+)` and calculated value of magnetic moment on the basis of `sqrt(n(n+2))` formula is 3.87 BM. which is lower than the expermental value of 4.40 BM. The reason for this difference is due to

Options

A. increase in number of unpaired electrons during determination
B. Some contribution of the orbital motion of the electrons to the magnetic moment
C. d-d transition
D. Experimental error

Answer

b