Medium Practice — Set 1

Quick Recap — Bohr, Spectra & Configuration Calculations

• $E_n=-\dfrac{13.6\,Z^2}{n^2}$ eV; $r_n=0.529\dfrac{n^2}{Z}$ Å; transition energy $=E_{high}-E_{low}$.
• Rydberg: $\dfrac{1}{\lambda}=R_H Z^2\!\left(\dfrac{1}{n_1^2}-\dfrac{1}{n_2^2}\right)$; spectral lines from level $n=\dfrac{n(n-1)}{2}$.
• Photon: $E(\text{eV})=\dfrac{1240}{\lambda(\text{nm})}$; de Broglie: $\lambda=\dfrac{h}{mv}$.
• Nodes: angular $=l$, total $=n-1$.