Atoms are those elements which can not be broken further. They are smallest particles that cannot be further divided. Atoms are made of protons, electrons and neutrons.
Atomic weight is weight of nucleus i.e. weight of protons and neutrons. Atomic weight of an element is that number which show how many times it is heavier than 1/16 part weight of oxygen or 1/12parts of carbon.
Atomic number is the number of protons present in the nucleus.
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