Question

$2.3\times {10}^{22}$ atoms of an element weighs 6.9 g. The atomic weight of that element is:

• A. $290g$
• B. $180g$
• C. $34.4g$
• D. $10.4g$

Answer 1

The correct option is B $180g$

$2.3\times {10}^{22}$ atoms of an element weighs $6.9$ g.

$6.02\times {10}^{23}$ atoms (1 mole) of an element will weigh $\frac{6.02\times {10}^{23}}{2.3\times {10}^{22}}\times 6.9=180$ g.

The atomic weight of that element is $180$ g/mol.

Hence, option $B$ is correct.