Question

Number of atoms in the following samples of substances is the largest in :

• A. 4.0 g of hydrogen
• B. 71.0 g of chlorine
• C. 127.0 g of iodine
• D. 48.0 g of magnesium

Answer 1

Answer: (A)

4g of hydrogen = 4 mole of hydrogen
= $4\times 6.023\times 10^{23}atoms$
$71.0g$ of chlorine = $\frac{71.0}{71.0}$ = $1$ mole of
chlorine = $6.023\times 10^{23}$ atoms.
$127g$ of iodine = $\frac{1}{2}$ mole of $I_2$
$=\frac{127}{254}=6.023\times 10^{23}\times \frac{1}{2}$ atoms.
$48.0g$ of magnesium
$=\frac{48.0}{24.0}=2\times 6.023\times 10^{23}$ atoms.
$\therefore 4.0g{H}_2$ has largest number of atoms.