What are termed as f-block elements?, Chemistry

Assignment Help:

The f-block elements contains of two series of inner transition elements i.e. lanthanoids (the fourteen elements subsequent lanthanum) and actinoids (the fourteen elements subsequent actinium). They are also called rate earth elements.

All the lanthanoids have electronic configuration with 6s2 common but with variable occupancy of 4f- and 5d- subshells. All actinoids have electronic configuration of 7s2 and variable occupancy of 5f- and 6d- subshells. These f-orbitals are placed to the shell third from the outer shell. This factor accounts for some characteristic properties of these elements. The members of lanthanoid and actinoids series are listed in the table below. Although lanthanum itself does not possess any 4f-electrons, it is customary to include this element in the discussion of lanthanoid series due to its close resemblance with lanthanoids. For lanthanoids the general symbol, Ln is often used. Similarly, actinium is studied alongwith actinoids. The electronic configuration of the elements with fully filled (f14) and half filled (f7) f-orbitals are relatively more stable. The extra stability of half filled orbitals is seen in the elements europium (4f7 6s2) and gadolinium (4f7 5d1 6s2). The element ytterbium has fully-filed f-orbitals with the configuration 4f14 6s2 and the extra electron in lutetium goes in 5d-orbitals (4f14 5d1 6s2). So except for lanthanum, gadolinium and lutetium which have a single electron in 5d-orbitals the lanthanoids do not have electrons in the 5d-orbitals.

Electronic configuration of Lanthanum and lanthanoids
1684_F-block elements.png          




Electronic configuration of actinium and actinoids

1209_F-block elements1.png


Related Discussions:- What are termed as f-block elements?

stability of carbocations in benzene ring, how to find stability of carboc...

how to find stability of carbocations in benzene ring..??? and how how to find optically inactive isomers  ??? (say of--C2H5Cl) how to find the weakest C-X (carbon-halogen bond in

Periodic table, the structure of a periodic table

the structure of a periodic table

Classification of dyes - direct dyes, Classification of dyes according to t...

Classification of dyes according to their application Direct dyes: this type of dyes can be directly applied to the fiber, both vegetable and animal, by dipping in hot aqueo

Qualitative analysis, why HNO3 is not used for detection of acidic radical ...

why HNO3 is not used for detection of acidic radical of 1st and 2nd group ions?

What is activation energy, The difference among Threshold energy and averag...

The difference among Threshold energy and average energy of the molecules is known as activation energy.

Which statement is not correc, Which statement is not correct for n=5, m=3:...

Which statement is not correct for n=5, m=3: (1) l=4                    (2) l=0, 1.3, s =+1/2            (3) l= 3                  (4) All are correct Ans:l=4

Periodic table, how periodic table is helpful in chemistry give two example...

how periodic table is helpful in chemistry give two example

Chemical equilibria, what do you know about the dynamic nature of chemical ...

what do you know about the dynamic nature of chemical equilibrium?

Diagram, caustic embrittlement

caustic embrittlement

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd