Question

Calculate the mass of 3×10^6 atoms of Al. ​

Answer 1

What we need to keep in mind ?

$A_0=6.022*10^{23}$

$m_{Al}=27g$

Now,

$A_0m=m_{Al_0}\\6.022*10^23m=27\\m=\frac{27}{6.022*10^2^3} \\m=4.483560278977084*10^{-23}g$

All we need to do next is

$A_1=3*10^6$

$m_{al_1}=A_1m\\m_{al_1}=4.483560278977084*10^{-23}*6*10^6\\m_{al_1}=26.9013616738625*20^-^1^7$

∴ $3*10^6$ atoms weight $26.9013616738625*10^{-17}$ g