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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...

                                            Vistas                                           Chapter -2                                      The Tiger King   “The Tiger King” is a story of an arrogant King who disproved the prophecy of the astrologer, but destiny proved to be powerful and the prediction which was made when the king was ten days old comes out to be true. The Maharaja Sir Jilani Jung Jung Bahadur was called “Tiger King”. When he was just 10 days old he asked intelligent questions to the astrologers and was told that he would be killed by a tiger. He uttered “Let tigers beware!” No other miracle took place, the child grew like any other Royal child drinking whit...

 The solar system consists of the Sun, which is a star at its center, and all the celestial bodies bound by its gravitational pull. These bodies include planets, moons, asteroids, comets, and other objects. Key Components of the Solar System: The Sun : The Sun is the center of the solar system and contains about 99.86% of its mass. It is a star primarily composed of hydrogen and helium, providing the heat and light that sustains life on Earth. Planets : There are eight recognized planets in the solar system: Mercury : The closest planet to the Sun, known for extreme temperature variations and no atmosphere. Venus : Similar in size to Earth but with a thick, toxic atmosphere and surface temperatures hot enough to melt lead. Earth : The third planet from the Sun, the only known planet to support life, with water and a breathable atmosphere. Mars : Known as the Red Planet, it has a cold, dry surface and signs of past water. Jupiter : The largest planet, a gas giant, w...

Newton's third law states that “ EVERY ACTION HAS EQUAL AND OPPOSITE REACTION. ” It is a contact action reaction pair which applies on the two or more different bodies.  There are the following types of contact forces are:- 1. Normal reaction :-  It is a perpendicular force acting at the point of contact between the bodies.  Weight of the body is calculated using Normal reaction.  Direction of Normal is always perpendicular to to the surface in such a way that it tries to compress the body.  Let m be the mass of the body and N is the normal reaction and g is the acceleration due to gravity.  Then -                     N = mg 2. Tension :-  This forces are mainly seen in strings. It is a action reaction force which act in opposite directions. 

 1. Mr. Lakshman, aged 65 years worked as a civil engineer in a construction company. He had to walk and climb a lot as part of his job. After retirement, he settled with his son spending time with his grandchildren. Now a days he is experiencing difficulty in doing certain chores which involves physical movement.  (i) Which of the following tests would you recommend to check Mr. Lakshman’s fitness? (a) Harvard step test  (b) Rikli & Jones test (c) AAHPER test (d) Rock port test (ii) How many series of tests are there in the prescribed fitness test for Mr. Lakshman? (a) 8  (b) 6 (c) 5  (d) 4 (iii) Chair sit & reach test is done to check ____________ (a) Agility (b) Speed (c) Flexibility (d) Strength (iv) Pick the odd one out. (a) Arm curl test (b) Chair stand test (c) 6 min walk test (d) Partial curl up (v) The 8 foot up &go test, as shown in the picture is performed to assess _________ (a) Agility (b) Endurance (c) Speed (d) Strength 2. (i) Both the...