Mass of a body is the quantity of matter in the body which does not depend on the temperature, pressure or location of the body in space.
The prototypes of the international bureau of weights and measures (BIPM) are available in many other laboratories of different countries.
In India, this is available at the national physical laboratory (NPL), in New Delhi.
While dealing with atoms and nucleus, there is a standard unit of mass, i.e 1 unified atomic mass unit
1 u = (1/12) of the mass of an atom of carbon-12
Isotope ₆C¹² including the mass of electrons = 1.66×10⁻²⁷ kg
For measurement of small masses of atomic/subatomic particles etc, we make use of a mass spectrograph.
Range Of Variation Of Mass
The masses of objects vary from 10⁻³⁰ kg (mass of an electron) to 10⁵⁵ kg (mass of the known universe).
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