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
How many grams of NaCl will be produced when 2235 g of HCl are neutralized by an excess of NaOH according to the equation below? HCl + NaOH ---> H2O + NaCl

Gustation - The Sense of Taste The word ‘taste' means not only a sensory response to the soluble materials in the mouth but also aesthetic appreciation. It has been noted many

The diffusion current for a standard 1 x 10-4 M solution of hydroquinone is found to be 17.5 µA. An unknown solution of hydroquinone, when diluted tenfold and analysed under simila

A baseball weighs 5.19oz oz . What is the kinetic energy in joules of this baseball when it is thrown by a major-league pitcher at 93.0mph mph ?

Line imperfection : Displacement with a curved boundary makes a mixed dislocation line at the boundary.

A monosaccharide A has a molecular weight of 150 Da. The two stereoisomers B and C that are both optically inactive form when A reacts with NaBH4.  Show all dissimilar stereoiso

Lowest set of locants - IUPAC system of nomenclature while two or more substituents are present, then end of the parent chain that provides the lowest set of the locants is pre

Suffix - IUPAC System of Naming Organic Compounds The word root is associated to the suffix that may be primary or secondary or both of them. (a) Primary suffix: A

Coordination number and geometry   Binary compounds are ones with two different elements present. 'Simple' crystal structures can be classed as ones in which each atom (or

Calculate the energy required to compress carbon dioxide from 1 bar to 50 bar (final volume is 50 ml, 298 K, ideal gas).