Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
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 Electronic configuration of actinium and actinoids
advantage of his theory?
dehydration of alcohol with mechanism
Q. Show the Occurrence of the f-block element? Apart from promethium which is unstable and is found in traces in uranium ores, all the lanthanides usually occur together. Altho
Q. in radioactive decay, a nucleus emits an alpha particle and two beta particle successively. show that the final nucleus is an isotope of original nucleus. Ans: Let the mass and
Q. Explain Basic physical properties of Gas? Ans. Gases are the least dense phase of matter. Gases can be easily expanded or compressed. They exert pressure equally in
The nature of bonding in graphite is: (1) Covalent (2) Ionic (3) Metallic (4) Coordinate Ans: Covalent
Melting and freezing points: When a pure solid substance is heated through its melting point (melting temperature), the solid changes to a liquid. At the melting point equilibr
Q. What is Alloys? Metals have a property of combining with other metals to form alloys. An alloy may be defined as a solid which is formed by a combination of two or more met
ester formation
what makes gum chewy
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!
whatsapp: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd