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Q.
Which sample contains the largest number of atoms ?
Solution:
$1\, mg\, C _{4} \,H _{10}=\frac{14 N }{58} \times 10^{-3}$ atoms
$1\, mg \,N _{2}=\frac{2 N \times 10^{-3}}{28}$ atoms
$1\, mg\, Na =\frac{ N \times 10^{-3}}{23}$ atoms
$1\, mL =1\, g\, H _{2} O =\frac{3 N }{18}$ atoms