If you where asked to convert 4.2*10^22 atoms of aluminum to moles, which of the following should you use for the conversion

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

where are the choice options?