Question

$x\times {10}^{18}$ (2 significant figures) $Cs$ - atom can be converted to ${Cs}^{+}$ ions by $1$ joule energy, if ${IE}_1$ for $Cs$ is $376kJ$ ${mol}^{-1}$. Find $10x$.

Answer 1

$376kJ$ for $6.022\times {10}^{23}$ atoms.

Therefore 1J energy for $\frac{6.022\times {10}^{23}}{376000}$ which comes out to be $1.6\times {10}^{18}$.

So, $x=1.6$ and $10x=16$

So, 16 is the correct answer