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Atomic Number, Mass Number, Isotopes, and Relative Atomic Masses of Atoms

Atomic numberThis is the number of protons (i e. number of positive charges) in the nucleus of any atom. Mass numberThis is the total number of protons and neutrons (collectively called nucleons) in the nucleus of the atom. IsotopesIsotopes are atoms of the same elements with the same atomic number but different mass numbers. The…

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Laws of Conservation of Matter, Constant Proportion and Multiple Proportion

Early history of chemistry was marked by incorrect theories about what occurred during chemical reactions. It had long been observed, for instance, that when wood burnt, the resulting ash was very light and fluffy. These types of observations then led to the conclusion that ‘something’, which German chemists, Becher and Stahl called phlogiston, was lost…

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