Rahul Dravid wants to wear $6.023\times {10}^{21}$ "Ag" atoms in the form of a ring. His 'Silver-Gold-Copper' alloy ring consists of $20\%$ of Silver. The mass of the ring is __________ grams.

 

Number of atoms of Silver given $=6.023\times {10}^{21}$

Avogadro's number $=6.023\times {10}^{23}$

Now, the mass of Silver $=$ moles $\times$ Atomic weight $(107.8)$

$=0.01\times 107.8=1.078$

Let, $M$ be the mass of the ring:

$\%=\frac{Givenmass}{Molecularmass}\times 100$

$$\begin{gathered} 20\%=\frac{1.078}{\mathrm{M}}\times 100 \\ \mathrm{M}=5.4 \mathrm{grams} \end{gathered}$$

Therefore, the mass of the ring is 5.4 grams.