callister7e_sm_ch04_14

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4-20 
 4.14 This problem calls for a determination of the number of atoms per cubic meter for lead. In order to 
solve this problem, one must employ Equation 4.2, 
 
 
N = 
N A ρPb
APb
 
 
The density of Pb (from the table inside of the front cover) is 11.35 g/cm3, while its atomic weight is 207.2 g/mol. 
Thus, 
 
 
N = (6.023 x 10
23 atoms /mol)(11.35 g /cm3)
207.2 g /mol
 
 
= 3.30 x 1022 atoms/cm3 = 3.30 x 1028 atoms/m3 
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