Question

What is the mass of one aluminum unit cell in grams?

Please show work, I am trying to understand this.

Answer 1

Aluminum crystal is FCC structure. So FCC has 4 atoms ( 1 from 8 crners and 3 from 6 faces)

1 mole of Al = 6.023*10^23 atoms

27g of Al = 6.023*10^23 atoms

mass of one Al atom = 27/6.023*10^23   = 4.48*10^-23 g

But unit cell contains 4 atoms = 4*4.48*10^-23g

                                               = 1.792*10^-22g >>>>>answer