The ionization energy of sodium in $\mathrm{~kJ} \mathrm{~mol}^{-1}$, if electromagnetic radiation of wavelength $242 \mathrm{~nm}$ is just sufficient to ionize sodium atom is _______.
Answer (integer)
494
Solution
<p>$$\begin{aligned}
& \mathrm{E}=\frac{1240}{\lambda(\mathrm{nm})} \mathrm{eV} \\
& =\frac{1240}{242} \mathrm{eV} \\
& =5.12 \mathrm{eV} \\
& =5.12 \times 1.6 \times 10^{-19} \\
& =8.198 \times 10^{-19} \mathrm{~J} / \text { atom } \\
& =494 \mathrm{~kJ} / \mathrm{mol}
\end{aligned}$$</p>
About this question
Subject: Chemistry · Chapter: Atomic Structure · Topic: Bohr's Model
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