1) masa molara a K(potasiu) =39.09 g/mol⇒78÷39.09=1.9954(moli)
un mol=6,022x10²³atomi⇒doi moli=2x(6,022x10²³)
2) masa molara a Al(aluminiu)=26.98 g/mol⇒0.5 · 26.98=13.49gr ⇒(6.023x10²³)÷2=3.011x10²³ atomi
3)masa molara a S(sulf)=32.065g/mol⇒in 160gr sunt 4.98986 moli⇒
un mol are 6.023x10²³ atomi⇒4.9898 moli au 30.05393 x10²³ atomi.