How many `g` atoms and number of atoms are there n (a) `60 g` carbon, (b) `22.4 g Cu`, an (c ) `72.52 g` lead. Given atomic masses of `C, Cu` and `Pb` are 12,63.6, and 207.2, respectively. (Avogadro's number `= 6.02 xx 10^(23))`.

Explanation

g atom = `("Weight")/("Atomic Weight")`
and number of atoms `= ("Weight xx N_(A))/("Atomic Weight")`
a. For `60 g C`:
g atom `= (60)/(12) = 5`
Number of atoms `= (224.4 xx 6.02 xx 10^(23))/(36.6) = 30.1 xx 10^(23)`
b. For `224.4 g Cu`:
g atom `= (224.4)/(63.6) = 3.35`
Number of atoms `= (224.4 xx 6.02 xx 10^(23))/(63.6) = 21.24 xx 10^(23)`
c. For `(72.52)/(207.2) = 0.35`
Number of atoms `= (72.52 xx 6.02 xx 10^(23))/(207.2) = 2.107 xx 10^(23)`