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

Ask an Expert

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

Write your message here..

Related Questions

Types of chromatography- purification of organic compounds, Types of chroma... Types of chromatography- Purification of organic compounds Depending on the nature of the stationary and the mobile phases, the different types of chromatographic methods gener

Pressure vs. mole fraction of cyclooctane , Consider a 2-component system o... Consider a 2-component system of cyclooctane(1) and styrene(2) at 350 °C. Both component can be well described with the Soave-Redlich-Kwong equation of state in the mixed vapor and

Ether formation - hydrocarbon, Ether formation - Hydrocarbon Phenol rea... Ether formation - Hydrocarbon Phenol reacts along with alkyl halides in alkali solution to make phenyl ethers (Williamson's synthesis). The phenoxide atom is a nucleophile and

Uses of catechol, Uses of Catechol Catechol finds use as photographic d... Uses of Catechol Catechol finds use as photographic developer and in the manufacture of alizarin and adrenaline hormone and like an antioxidant (inhibitor in auto oxidation) fo

The concept of energy, what is point function what is point function

#title., i just need to know if anyone that might know of a website that ha... i just need to know if anyone that might know of a website that has the answer key to the book chemistry Prentice Hall Brief Review 2013

Define colligative properties of a dilute solution, Define Colligative Prop... Define Colligative Properties of A Dilute Solution? The colligative properties of a solution are usually considered to be: 1. Freezing-point depression: the decrease in the

Molality and molarity, the density of 2 molal aqueous solution of NaOH is 1... the density of 2 molal aqueous solution of NaOH is 1.10g/L. Calculate the molarity of the solution.

Iupac names for polfunctional structures, some structures containing polyfu... some structures containing polyfunctional groups

Determine electron if the uncertainty in velocity, For an electron if the u... For an electron if the uncertainty in velocity is  Δ v , the uncertainty in its position( Δ x )  is given by: (1) hm/ 4 Π Δ b                            (2) 4  Π / hm  Π v