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  Diagonal Relationship between Beryllium and Aluminium The ionic radius of Beryllium (Be 2+) is estimated to be nearly 31 pm; the charge/radius ratio Or e/m ratio is nearly the same as that of the Al 3+ ion. Hence beryllium resembles aluminium in these ways. Some of the similarities are given below: » Like Aluminium, Beryllium(be) is not readily attacked by acids H+ donor because of the formation of an oxide film on the surface of the metal by reacting with oxygen, i.e. they are rendered passive by nitric acid. » Beryllium hydroxide[[Be(OH)4]2] dissolves in excess of alkali to give a beryllate ion, [ Be(OH)4]2– just as aluminium hydroxide[Al(OH)3] gives aluminate ion, [Al(OH)4] » The chlorides of metals beryllium and aluminium have Cl– bridged chloride structure in vapour phase. Both the chlorides are soluble in organic solvents and are strong as Lewis acids They are used as Friedel Craft catalysts. » Beryllium(Be) and aluminium(Al) ions have strong tendency to form complexes, (Be...

  ANOMALOUS BEHAVIOUR OF BERYLLIUM Beryllium(Be) is the first member of the Group 2 metals, which shows anomalous behaviour as compared to Magnesium(Mg) and rest of the members. Further, it shows diagonal relationship with aluminium. » Beryllium(Be) has exceptionally small atomic and ionic sizes and thus does not compare well with other members of the group. Because of the high ionisation enthalpy(energy required to remove an electron from isolated gaseous ion) and smaller size it forms compound which are largely covalent and get easily hydrolysed. » Beryllium(Be) do not exhibit coordination number more than 4 as in its valence shell there are four orbitals. The remaining member of this group can have a coordination number of 6 by making use of d-orbitals. » The oxide and hydroxide(OH) of beryllium(be), unlike the hydroxides of other elements in the group, are amphoteric in nature. » The beryllium hydride is electron deficient and polymeric, with multi-center bonding like aluminium...

The similarity between lithium and magnesium is particularly striking and arises because of their similar size: atomic radii, L i = 152 pm, Mg = 160 pm; ionic radii : L i+ = 76 pm, Mg 2+ = 72 pm.  The main points of similarity are :  » Both lithium and magnesium are harder and lighter than other elements in the respective groups. » Lithium and magnesium react slowly with water. Their oxides and hydroxides are much lesser soluble and their hydroxides decomposes on heating. Both forms a nitride,  Li 3  N and  Mg 3   N 2 , by direct combination with nitrogen( N 2)  .  » The oxides,  Li 2  O and Mg O do not combine with excess oxygen to give any superoxide. » The carbonates of lithium and magnesium decompose easily on heating to form the oxides and C O 2  . Solid hydrogen carbonates are not formed from lithium and magnesium.   »Both L i Cl and  Mg Cl 2  are soluble in ethanol.  » Both L i Cl and  Mg Cl 2...

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    ANOMALOUS PROPERTIES OF LITHIUM The anomalous behaviour of lithium is due to the : (i) exceptionally small size of its atom and ion, and (ii) high polarising power (i.e., charge/ radius ratio ). As a result, there is a increase in covalent character of lithium compound which is responsible for their solubility in the organic solvent. Further, lithium shows diagonal relationship to magnesium.  Atomic number                            3 Group                                             1  Period                                             2 Block                                  ...

                    INTRODUCTION : The s- block elements of the periodic table are those in which the last electron enters  into the outermost s-orbital. As the s-orbital can accommodate only two electrons, in two group (1 & 2) belong to the s-block of the periodic table. Group 1 of the periodic table consists of the elements : lithium (L i), sodium (Na), potassium (K), rubidium (R b), caesium (C s) and francium (F r). They are collectively known as alkali metals. These are called because they forms hydroxides on reaction with water which are strongly alkaline in nature. The elements of Group 2nd include beryllium (Be), magnesium (Mg), calcium (C a), strontium (S r), barium (B a) and radium (Ra). These elements with the exception of Beryllium are commonly known as the alkaline earth metals. These are so called because their oxide and hydroxide are alkaline in nature and these metal oxides are found in the earth’s crust . The ge...

Ques 1 : What is physical education? Explain the aim and objectives of physical education.  Ans : Physical education is a very vast subject and it has been given importance since ages. Modern trends have increased its importance as modern physical education stresses on balanced development of body and mind. It brings harmonious growth and development so that optimum health as well as good personality can be developed.  Physical education is studied as a regular subject at per with other academic subjects. The activities of physical education programmes are used by other academic subjects for better learning. This subject has been found to develop good health. Its activities are also followed for disabled students, occupational and professionalism of other subjects. Thus, we can say that physical education has great importance in the society, moreover, the trends in physical education and sports are also changing.  Physical Education refers to the instructions of phys...

Ques 1: “Physical Eduction is the sum of changes in an individual caused by experience centring motor activity” Who said this? (a) Prince martin  (b) Millions (c) Charls A.Butchar  (d) Cassidy Ans :  (d) Cassidy Ques 2: “Physical Education is the sum of men’s physical activities selected as to kind and conducted as to outcomes” who said this? (a) C.C.Covel  (b) Charls A Butcha (c) Williams  (d) J.B. Nash Ans :  (c) Williams Ques 3 : How many objectives of physical Education are there? (a) Four  (b) Five (c) Three  (d) Six Ans : (b) Five Ques 4 : What is the aim of physical Education? (a) Physical development  (b) Motor development (c) Mental Development  (d) All Round development Ans : (d) All Round development Ques 5: Sports management is based upon....? (a) Efficient and Talented officials  (b) Smart and clever officials (c) Weak and Greedy officials  (d) None of these  Ans : (a) Efficient and Talented of...

Ques 1 : What do you mean by sports journalism? Ans : In sports journalism we mean that we can gather information regarding all sports activities and to collect all different types of material required for physical education. Such physical education teachers who have skill in communicating by oral or writing can avail their career option in the field of sports journalism.  Ques 2 : What do you mean by Health related careers? Ans : In the modern world, people are more aware of their health and health related issues. Each and every person is curious about their health. He remain to be hale and healthy. He wants to adopt a healthy life style. So there is an increment in job opportunities in health related careers in field of physical education. The no. of health and weight control clubs has increased tremendously. The another career related to health career is athletics training.  Ques 3 : What is the objective of physical education? Ans : The main obje...

                        Introduction The importance of sports and fitness in one’s life is invaluable. Playing sports inculcates team spirit, develops strategic and analytical thinking, leadership skills, goal setting and risk taking. Moto of Khelo India Program is “A fit and healthy individual leads to an equally healthy society and strong nation”.  Sports is an extremely important component for the overall development of our nation or for any nation. India, in the last five years has made steady progress in the field of sports. This tremendous potential need to be show cased at a global platform. It’s time we inspire young talent, give them top notch, infrastructure and training of the highest level. We need to inculcate a strong spirit of participation in the sports that enables players to demonstrate their true potential. Only then India can  realise its dream of becoming a sports super power.  The...

1. Meaning and Definition of Physical Education Physical Education is composed of two words Physical and Education. ‘Physical’ means body and ‘Education’ means modification of behaviour thus means Education through the medium of physical Activities. It aims on overall development of human being through participating in various games and sports activities. Modern Physical Education was started in 18 century in Germany. Where Physical Education was an integral part of School Curriculum, Since then many changes have taken place and various aspects have emerged with time.  1.1 Definitions of Physical Education: In fact the basis of the physical education is difficult and very broad changing with time, its meaning also kept changing. Following time, its meaning: According to Charles A Bucher, "physical education is an integral sum part of  the total education process and has its aim in the development of physically, mentally, emotionally and socially fit citizens through the med...