Answer:
0.0697 moles
Explanation:
We are being asked 4.2 x 10^22 atoms of aluminium to moles the following should be used for conversion.
Fraction of 1 mole Al over six point zero two two times ten to twenty third power atom Al.
that is 1 mole = 6.022 x10^23 atom
? = 4.2 x 10^22 atom
by cross multiplication
(1 mole x 4.2 x 10^22)/ 6.022 x 10^23 = 0.0697 moles
