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!
Q. General Characteristics of the f-block?
You know that the 14 elements from cerium (Z = 58) to lutetium (Z = 71), which follow lanthanum (Z = 57) in the periodic table, are known as lanthanides, lanthanons or lanthanoids. Note that some authors include lanthanum also in lanthanides, but there IS no general agreement on it. These elements are characterised by successive filling of 4f orbitals in their atoms. These elements along with yttrium and lanthanum were originally known as rare earth elements or simply rare earths. The word 'earth' was used because they occur as oxides, which in early usage meant earth, and the word rare was used because of the great hard in their separation from each other. Otherwise, these are not particularly rare in earth's crust. For illustration, lanthanum, neodymium and cerium are more abundant than lead. Even the scarcest of them, thulium, is as abundant as bismuth and more abundant than arsenic, cadmium, selenium, or mercury none of which is usually considered rare.
The fourteen elements from thorium (Z = 90) to lawrencium (2 = 103) following actinium in the periodic table are define as actinides, actinoids or actions. They are analogous to the lanthanides and result from the filling of the of orbitals as the lanthanides result from the filling of 4f orbitals. Prior to 1940, only the obviously occurring actinides, i.e., thorium, protactinium and uranium were known. The remaining actinides have been produced artificially since then and are collectively define as transuranium elements.
Important reaction
Limitations of flame photometry: The limitations of the techniques involve the following. The low temperature of the natural gas and air flame limits a method to simply
Separation of alkane, alkene and alkyne The gaseous mixture is passed via ammonical cuprous chloride solution. The alkyne (acetylene) reacts along with and makes a red preci
what is back titration
OSTWALDS DILUTION LAW IS APPLICABLE TO WHAT
Uses of Alkenes (i) Alkenes are used for the manufacture of polythene - a plastic material; (ii) Alkenes are used for artificial ripening of fruits; (iii) Alkenes are us
Vulcanization of rubber The procedure of heating natural rubber with sulphur to enhance its properties is known as vulcanization. Vulcanization was illustrated by Charles Goody
Glucose and fructose differ in their structer at 1st two carbon atom c1 and c2 only.In osazone formation tthere two carbon atoms take part in the reaction and during osazone format
Q. What is Geometrical isomers? Let us take one final example of Ma 2 b 2 cd where the following five isomers are possible as shown in Fig. 'When writing the geometrica
can i have some reactions of p block elements such as in water,with oxygen,in acid etc...
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