Atomic Mass Unit (amu): This is a standard unit that is used for indicating mass on an atomic or molecular scale. One atomic mass unit is roughly equivalent to the mass of one proton or neutron.
Mole:A basic measuring unit in chemistry which denotes a specific amount (6.022 x 10^23) of elementary entities, such as atoms, molecules, electrons etc.
Avogadro's Number:This number, which equals 6.022 x 10^23 entities per mole, was named after scientist Amedeo Avogadro who contributed significantly to molecular theory and gas laws.