Which among the following elements has highest number of atoms in $1 \mathrm{~g}$ each ? (at. no.…
Which among the following elements has highest number of atoms in $1 \mathrm{~g}$ each ? (at. no. $\mathrm{Au}=197, \mathrm{Na}=23, \mathrm{Cu}=63 \cdot 5, \mathrm{Fe}=56$ )
$\mathrm{Cu}_{(\mathrm{s})}$
$\mathrm{Na}_{(\mathrm{s})}$
$\mathrm{Au}_{(\mathrm{s})}$
$\mathrm{Fe}_{(\mathrm{s})}$
Solution
i. $1 \mathrm{~g} \mathrm{Fe}=\frac{1}{56} \mathrm{~mol}=\frac{1}{56} \times 6.022 \times 10^{23}$ atoms of $\mathrm{Fe}$
ii. $\lg \mathrm{Au}=\frac{1}{197} \mathrm{~mol}=\frac{1}{197} \times 6.022 \times 10^{23}$ atoms of $\mathrm{Au}$
iii. $1 \mathrm{~g} \mathrm{Na}=\frac{1}{23} \mathrm{~mol}=\frac{1}{23} \times 6.022 \times 10^{23}$ atoms of $\mathrm{Na}$
iv. $\lg \mathrm{Cu}=\frac{1}{63.5} \mathrm{~mol}=\frac{1}{63.5} \times 6.022 \times 10^{23}$ atoms of $\mathrm{Cu}$
Hence, $1 \mathrm{~g}$ of Na has highest number of atoms.