a/ \(m_{Fe}=56.0,16605.10^{-23}=9,2988.10^{-23}\left(g\right)\)
b/ \(m_{Cu}=2.64.0,16605.10^{-23}=21,2544.10^{-23}\left(g\right)\)
c/ \(m_{Na}=10.23.0,16605.10^{-23}=38,1915.10^{-23}\left(g\right)\)
m Fe=56.0,16605.10-23=9,2988.10-23g
m Cu=64.2.0,16605.10-23=2,12544.10-22g
m Na=23.10.0,16605.10-23=3,81915.10-22g