• $summary_{type}$: application
• $word_{count}$: 180

Five named series cover the entire hydrogen emission spectrum. Lyman series ($n_f$ = 1): all transitions ending at n=1, located in the ultraviolet. First line (Lyman-alpha, 2 to 1) at 121.6 nm, series limit at 91.2 nm. Balmer series ($n_f$ = 2): transitions to n=2, partly in the visible region. H-alpha (3 to 2) = 656.3 nm (red), H-beta (4 to 2) = 486.1 nm (blue-green), H-gamma (5 to 2) = 434.0 nm (violet). Series limit at 364.6 nm. Paschen series ($n_f$ = 3): infrared, first line at 1875 nm (4 to 3). Brackett ($n_f$ = 4) and Pfund ($n_f$ = 5) are in the far infrared. Mnemonic: "Lazy Boys Play Basketball Poorly" for $n_f$ = 1, 2, 3, 4, 5. The number of spectral lines when atoms are excited to level n is n$\frac{n-1}{2}$. From n=4: 6 lines (3 Lyman + 2 Balmer + 1 Paschen). JEE commonly asks to identify the series from a given wavelength range or to calculate the shortest/longest wavelength in a series.