1. Science

3. KEY

4. Noble gases All the elements of Group 18, the noble gases, have full valence shells. This means they do not need to react with other elements to attain a full shell, and are therefore much less reactive than other groups. Helium is the most inert element among noble gases, since reactivity, in this group, increases with the periods: it is possible to make heavy noble gases react since they have much larger electron shells. However, their reactivity remains low in absolute terms. Halogens In Group 17, known as the halogens, elements are missing just one electron each to fill their shells. Therefore, in chemical reactions they tend to acquire electrons (the tendency to acquire electrons is called electronegativity). This property is most evident for fluorine (the most electronegative element of the whole table), and it diminishes with increasing period. As a result, all halogens form acids with hydrogen, such as hydrofluoric acid, hydrochloric acid, hydrobromic acid and hydroiodic acid, all in the form HX . Their acidity increases with higher period, for example, with regard to iodine and fluorine, since a large I- ion is more stable in solution than a small F-, there is less volume in which to disperse the charge. Transition metals For the transition metals (Groups 3 to 12), horizontal trends across periods are often important as well as vertical trends down groups; the differences between groups adjacent are usually not dramatic. Transition metal reactions often involve coordinated species. Lanthanides and actinides The chemical properties of the lanthanides (elements 57-71) and the actinides (elements 89-103) are even more similar to each other than the transition metals, and separating a mixture of these can be very difficult. This is important in the chemical purification of uranium concerning nuclear power. Classification Example

5. Sir C.V. Raman, (1888 – 1970) 1930 - Nobel Laureate in Physics for work on scattering of light and Raman effect. Sir Jagdish Chandra Bose, (1858 – 1937) USA based IEEE has proved what has been a century old suspicion amongst academics that the pioneer of wireless-radio communication was Professor Jagdish Chandra Bose and not Guglielmo Marconi. Satyendranath Bose, (1894-1974) Indian Physicist , who solved one of the mysteries of quantum mechanics, showing that in the quantum world some particles are indistinguishable. His collaborations with Albert Einstein led to a new branch on statistical mechanics know commonly known as the “Einstein-Bose” statistics. Scientists / Economists

6. Srinivasa Ramanujam,(1887 – 1920): Great Indian Mathematician , whose interest from academics at Trinity, College, Cambridge, led him to collaborate there and postulate and prove well over 3,542 theorems. Amartya Sen, (b-1933): 1998 - The Nobel Prize for Economics for his redefining work on ethical welfare economics. Currently residing as Lamont University Professor Emeritus at Harvard, after stepping down from the prestigious post of Master of Trinity College, Cambridge. Subramanyan Chandrasekhar, (1910-1995): 1983 Nobel Laureate in Physics . His many contributions to physics, on the structure and evolution of stars including rotational figures of equilibrium, stellar interiors, black holes, radiative transfer, hydromagnetic stability, stellar dynamics. Har Gobind Khorana, (b-1922 ): 1968 - Nobel Laureate in Medicine for work on interpretation of the genetic code . Currently residing as professor at MIT.