Question

Which of the following has least mass?

• A. $2g$ atom of nitrogen
• B. $3\times {10}^{23}$ atom of $C$
• C. $1$ mole of $S$
• D. $7.0g$ of $Ag$

Answer 1

The correct option is B $3\times {10}^{23}$ atom of $C$

(a) $2gm$ atom of nitrogen $=28gm$

(b) $6\times {10}^{23}$ atoms of $C$ has mass $=12gm$

$3\times {10}^{23}$ atoms of $C$ has mass $=\frac{12\times 3\times {10}^{23}}{6\times {10}^{23}}=6gm$

(c) $1$ mole of $S$ has mass $=32gm$

(d) $7.0gm$ of $Ag$

So, lowest mass $=6gm$ of $C$.