Illustrate Magnetic properties of f-block element, Chemistry

Q. Magnetic Properties of f-block element?

You have learnt in the preceding unit-that paramagnetism is related with the presence of unpaired electrons in a substance. The actinide and lanthanide ions,  other than type (e.g.  La3+, Ce4+, Ac3+, Th4+, Pa5+, U6+, and f14 type ( e, g Yb2+ Lu3+ Lr3+paramagnetic, due to each of the seven f orbitals charactering inner -transition metal  species (lanthanide and actinide) must have a single electron before any pairing can take  place (Hund's rule).

You have also studied that in case of transition elements; the contribution of orbital motion of electrons to paramagnetism is negligible and will be ignored. The magnetic moments of transition metal ions can be explained in terms of unpaired electrons present in d-orbitals.  But the magnetic moments of only those lanthanide ions, which have,f0 f7and f14 configuration agree with the spin only value. In all other cases, the magnetic moment value are higher than those evaluated on the basis of spin only formula. Though, these can be explained by taking orbital contribution to magnetic moment also into account. In lanthanide ions, the 4f orbitals are comparatively better shielded from the surroundings by the overlying 5p and 5s orbitals than the d orbitals in transition metal ions. Thus, the contribution of orbital motion to paramagnetism is not quenched. 

Although actinides show a variation in magnetic properties same to that of the lanthanides, the magnetic properties of the actinide ions are more complicated than those of the lanthanide ions. This in part arises from (i) the fact that the 5f electrons are nearer the surface of the atom and are easily influenced by the chemical environment; although not to the similar extent as do the d electrons, and (ii) the less sharply illustrate distinctions between 5f and 6d electrons as compared with 4f and 5d electrons. From the above discussion it is clear that the magnetic moments of the f-block (inner transition) metal ions have to be calculated taking into account both spin and orbital contributions.

Posted Date: 7/12/2013 6:36:40 AM | Location : United States







Related Discussions:- Illustrate Magnetic properties of f-block element, Assignment Help, Ask Question on Illustrate Magnetic properties of f-block element, Get Answer, Expert's Help, Illustrate Magnetic properties of f-block element Discussions

Write discussion on Illustrate Magnetic properties of f-block element
Your posts are moderated
Related Questions
What is basically Gibb''s free energy change? Ans) The energy associated with a chemical reaction that can be used to do work.  The free energy of a system is the sum of its entha

A covered glass tube contains 2.25g of copper and 3.32g of sulphur. The mass of the tube as well as its contents is 18.48 g. Upon heating a chemical reaction forms copper(II) sulph

The gas stream from a sulfur burner is composed of 15-mol% SO 2 , 20-mol% O 2 , and 65-mol% N 2 .  This gas stream at 1 bar and 680°C enters a catalytic converter, where the SO 2

Why cyclo propane is more stable than cyclohexane

dehydration of alcohol with mechanism

The transition metal complexes are known to be paramagnetic in character. CFT helps us to understand the magnetic properties in terms of magnetic susceptibility measurements. The m

what is the symmetry of a star

how much time will it require to spend 0.1 mole of rupees when the average rate of expenditure is 1 billion rupees per second?

Which one of the following configuration represents a noble gas: (1) 1s 2 , 2s 2 , 2p 6 , 3s 2 ,       (2)1s 2, 2s 2, 2p 6 , 3s 1         (3) 1s 2 , 2s 2 , 2p 6 ,

plz explain the magnetic anisotropic effect in acetylene and ethylene?