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?

Mathematical method of expressing the concentrations of solu, how many gram...

how many grams of salt must be added to 500 gram of water in preparation of 12% saline solution

Vitamin, #question describe the water soluble water? ..

#question describe the water soluble water? ..

What numerical prefixes indicate in ligands, Q. What Numerical prefixes ind...

Q. What Numerical prefixes indicate in ligands? In any complex species, the ligands are quoted in alphabetical order, without regard to charge, before the name of the central m

Hybrid propellants - types of rocket propellants, Hybrid propellants: T...

Hybrid propellants: These propellants are the propellants which contain solid fuel & a liquid oxidiser. For instance, liquid N 2 O 4 or liquid oxidizer and acrylic rubber (s

Hess law, ?H value obtained for the reaction NH3 + HCl –› NH4Cl using t...

?H value obtained for the reaction NH3 + HCl –› NH4Cl using the thermodynamic data in your lab procedure?

Bond strength in hydrocarbons, Bond strength in hydrocarbons As much sh...

Bond strength in hydrocarbons As much shorter is the bond size, the greater is the compression among molecules atomic nuclei and therefore greater is the strength of that bond.

Titration of hcl with standard sodium carbonate solution, how do you calcul...

how do you calculate the concentration of hcl solution if you are the mass of sodium carbonate and the volume of its solution and the volume of the pipetted solution and the volume

Atom, two reasons why is it necessary to ionise chromium atomsin a sample

two reasons why is it necessary to ionise chromium atomsin a sample

What is point imperfection, Point imperfection: They are imperfect point-l...

Point imperfection: They are imperfect point-like regions in the crystal. One or two atomic diameters are the typical size of a point imperfection. A substitution impurity and an

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