Balmer Series 1 - Physics Demonstrations - Balmer Series 1 | Physics Undergraduate Labs

Hydrogen discharge lamps operate at high voltage (typically 5-10 kV). Ensure the lamp housing is properly grounded and connections are secure. Do not touch the lamp while in operation. Allow adequate cooling time before handling after use.

Purpose

Students observe the discrete visible spectral lines of hydrogen using handheld diffraction gratings, providing direct evidence of quantized atomic energy levels. The Balmer series lines (red, blue-green, violet) correspond to transitions from higher levels down to $$n = 2$$ .

$Hydrogen discharge tube glowing purple-white, mounted vertically in a housing with a DANGER high-voltage label; to the left, the diffraction spectrum shows distinct colored emission lines against a dark background$

Figure 1: The hydrogen lamp produces discrete spectral lines visible through a diffraction grating. The prominent lines correspond to the Balmer series transitions: red H-α (656 nm), blue-green H-β (486 nm), and violet H-γ (434 nm).

Safety Warnings

Danger: High Voltage Warning

Purpose