Considering the change of units, there are 2.27×10²⁵ atoms of carbon per pound.
You know that there are 6.02x 10²³ atoms of carbon per 12 grams.
On the other hand, you must make a change of units. For that you must know that 1 gram equals 0.00220462 pounds. Then you can apply the following rule of three: if 1 gram is equal to 0.00220462 pounds, 12 grams is equal to how many pounds?
[tex]mass=\frac{12 gramsx0.00220462 pounds}{1 gram}[/tex]
mass= 0.0264555 pounds
12 grams equals 0.0264555 pounds. So if 12 grams contains 6.02x 10²³ atoms, 0.0264555 pounds contains that many moles. Then you can apply the following rule of three: if 0.0264555 pounds contains 6.02x 10²³ atoms, does 1 pound contain how many atoms?
[tex]amount of atoms=\frac{1 poundx6.02x10^{23} atoms}{0.0264555 pounds}[/tex]
amount of atoms= 2.27×10²⁵ atoms
Finally, there are 2.27×10²⁵ atoms of carbon per pound.
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