Au are masa molara M=197g/mol si numarul de masa A= 79=p⁺+n⁰(total 79 nucleoni)
ro=m/v---> m=ro x v =19,3g ...... atat cantareste 1cm³aur
a) 5,8484x10²²atomi...cantaresc 19,3g
1at....................................................x=3,3x10⁻²² g
b) se stie ca 1mol Au, adica 197g contine N,A atomi(numarul lui Avogadro
1g.....................x= 6,023x10²³/197at=0,03x10²³at
c) 1cm³.......5,8484x10²²at dar
1atom.............79 nucleoni(p⁺+n°)
5,8484x10²²..........x=464x10²²nucleoni
