Q. The half life period of an isotope is 2 hours. After 6 hours what fraction of the initial quantity of the isotope will be left behind?

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Q. The number of waves made by an electron moving in an orbit having maximum magnetic quantum number is +3

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Q. The number of atoms present in 21.6 gram of silver (atomic weight = 108) are same as the molecules in

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Q. The National Chemical Laboratory is situated in

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Q. Equal masses of oxygen, hydrogen and methane are kept under identical conditions. The ratio of the volumes of gases will be

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Q. The mass number of an atom is equal to

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Q. The maximum number of covalent formed by nitrogen is

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Q. The formula C6H5-CO-CH3 represents

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Q. The metal that is usually extracted from sea water is

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Q. The method of concentrating the ore which makes use of the difference in density between ore and impurities is called

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Q. The inert gases are ____ in water

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Q. The molecular formula of phosphorous is

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Q. The names of the scientists, Newlands, Mendeleev, and Meyer are associated with the development of

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Q. Chlorofluorocarbons are primarily used as

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Q. Chlorofluorocarbons are replacing with less harmful compounds such as

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Q. In the upper atmosphere, the presence of chlorofluorocarbons causes the depletion of

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Q. Organic compound chlorofluorocarbon contains volatile derivative of ethane, methane and propane which are

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