Colorful Flames - Physics Demonstrations - Colorful Flames | Physics Undergraduate Labs

Multiple open flames present fire hazards. Keep candles away from paper, curtains, and flammable materials. Have a fire extinguisher readily accessible. Do not leave burning candles unattended. Establish a clear safety perimeter around the demonstration area.

Purpose

Metal-compound candles produce colored flames with characteristic emission lines visible through a diffraction grating on a document camera. Students see direct visual evidence that atoms emit discrete wavelengths — not a continuous spectrum — providing a compelling introduction to energy quantization.

$Four colored candles burning in a foam base (purple, green, yellow, and red flames from bottom to top) with their diffracted emission spectra visible to the right, showing distinct colored lines for each flame$

Figure 1: Four metal-compound candles burning in a foam base, viewed through a diffraction grating on a camera. Each flame's discrete emission lines are visible to the right of the direct image.

Medium Diffraction Grating

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Colorflame Candles

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Safety Warnings

Warning: Open Flame Hazards

Purpose