Question

what weight of calcium contains the same number of atoms as those in a 3 g of carbon?

Answer 1

$$\begin{gathered} \text{Dear Student,} \\ 12\mathrm{g}\mathrm{of}\mathrm{carbon}\mathrm{contains}=6.023\times {10}^{23}\mathrm{atoms} \\ 3\mathrm{g}\mathrm{of}\mathrm{carbon}\mathrm{contains}=\frac{6.023\times {10}^{23}}{12}\times 3\mathrm{atoms}=1.505\times {10}^{23}\mathrm{atoms} \\ \mathrm{Weight}\mathrm{of}6.023\times {10}^{23}\mathrm{atoms}\mathrm{of}\mathrm{calcium}=40\mathrm{g} \\ \mathrm{Weight}\mathrm{of}1.505\times {10}^{23}\mathrm{atoms}\mathrm{of}\mathrm{calcium}=\frac{40}{6.023\times {10}^{23}}\times 1.505\times {10}^{23}=9.9\mathrm{g} \\ 9.9\mathrm{g}\mathrm{of}\mathrm{calcium}\mathrm{contain}\mathrm{the}\mathrm{same}\mathrm{number}\mathrm{of}\mathrm{atoms}\mathrm{as}\mathrm{those}\mathrm{in}3\mathrm{g}\mathrm{of}\mathrm{carbon}. \\ \mathrm{Regards} \end{gathered}$$