How many atoms are in 44.8 g of pure aluminum? 44.8 g Al= Al atoms

Answer 1

first convert grams into moles

mass of Al given in problem in grams * ( 1 mol / atomic mass of Al in grams)

44.8g * (1 mol / 26.982g)

(this causes the unit of grams to cancel leaving units of moles)

= 1.66 mol

Use avagadros number to convert into atoms of Al

Avagadros number (this number is a constant) = 6.022E23 or 6.022*10^23

1.66 mol * (6.022*10²³ atoms / 1 mol)

(this causes the unit of mol to cancel leaving units of atoms)

= 9.996*10²³

Final answer = 10.0*10²³ or 10.0E23 atoms (3 sig-figs)