Spectral series: Lyman(UV), Balmer(Visible only), Paschen/Brackett/Pfund(IR). Lines from n = n(n−1)/2. Rydberg: $\frac{1}{\lambda} = R_H\left(\frac{1}{n_1^2} - \frac{1}{n_2^2}\right)$

Bohr model: $E_n = -\frac{13.6Z^2}{n^2}$ eV; $r_n = \frac{0.529n^2}{Z}$ Å; v_n = $2.18 \times 10^{6}$Z/n m/s. Energy most negative at n=1 (ground state). KE = −E_n; PE = 2E_n.

Photoelectric effect: KE = h(ν − ν_{0}). Below ν_{0}: NO emission. Intensity → electron count (not KE). de Broglie: λ = h/mv. Heisenberg: $\Delta x$·$\Delta p$ ≥ h/4π.

Quantum numbers: l = 0 to n−1 (l < n always). mₗ = −l to +l. Nodes: total=n−1, angular=l, radial=n−l−1. Electrons: subshell = 2(2l+1), shell = 2$n^{2}$.

Anomalous configs: Cr=[Ar]3$d^{5}$4$s^{1}$; Cu=[Ar]3$d^{10}$4$s^{1}$ (half/full d stability). Cations: remove 4s before 3d. $Fe^{3+}$=[Ar]3$d^{5}$ (5 unpaired $e^{-}$, maximum paramagnetism).