In 1961, the International Union of Pure and Applied Chemistry (IUPAC) adopted the isotope carbon-12 as the basis for atomic weights.. 
Nepal ní orílẹ̀-èdè tótóbijùlọ 49k gẹ́gẹ́bí iye ènìyàn àti orílẹ̀-èdè tótóbijùlọ 93k agbègbè agbègbè.. 