A lead atom has a mass of 3.4X10-²². How many lead atoms are in a cube of lead that has a volume of 2.00cm3 if the density of lead is 11.3g/cm3?
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find mass of Lead
(2.00 cm3) (11.3 g / cm3) = 22.6 grams of lead
How many lead atoms
(22.6 grams of lead) (1 lead atom / (3.4X10-²² grams) = 6.64 X 10^22 atoms of lead
since your mass of lead, 3.4X10^-22 , has only 2 sig figs showing,
you might be expected to round your answer off to
6.6 X 10^22 atoms of lead
(2.00 cm3) (11.3 g / cm3) = 22.6 grams of lead
How many lead atoms
(22.6 grams of lead) (1 lead atom / (3.4X10-²² grams) = 6.64 X 10^22 atoms of lead
since your mass of lead, 3.4X10^-22 , has only 2 sig figs showing,
you might be expected to round your answer off to
6.6 X 10^22 atoms of lead