any division of quantity accepted as a standard of measurement or exchange

unit of mass for expressing masses of atoms or molecules

the sum of the number of neutrons and protons in an atomic nucleus

any of the units of the avoirdupois system of weights

a decimal unit of weight based on the gram

a unit of mass equal to the mass that accelerates at 1 foot/sec/sec when acted upon by a force of 1 pound; approximately 14.5939 kilograms