Structure Of Atom Question 12
Question 12 - 2024 (31 Jan Shift 1)
The ionization energy of sodium in $\mathrm{kJmol}^{-1}$. If electromagnetic radiation of wavelength $242 \mathrm{~nm}$ is just sufficient to ionize sodium atom is ________.
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Answer (494)
Solution
$\mathrm{E}=\frac{1240}{\lambda(\mathrm{nm})} \mathrm{eV}$
$=\frac{1240}{242} \mathrm{eV}$
$=5.12 \mathrm{eV}$
$=5.12 \times 1.6 \times 10^{-19}$
$=8.198 \times 10^{-19} \mathrm{~J} /$ atom
$=494 \mathrm{~kJ} / \mathrm{mol}$
