Portrait of Morris Travers

Adapted from ⁠an image by The Cyclopedia Publishing Company, Calcutta (public domain), via Wikimedia Commons.

1872–1961

Morris Travers

Discovered three elements.

Elements

Travers and Ramsay identified neon by the crimson glow of its spectrum. Explore the lines that gave it away.

Emission spectrum

A fingerprint made of light

Neon’s many red and orange lines give neon signs their colour. Signs in other colours usually use other gases, or tubes coated on the inside.

Electrons race through the tube and crash into neon atoms, knocking the atoms’ own electrons up to higher energy levels. As those fall back, the atoms give off light only at the exact wavelengths below, so each gas glows its own colour.

The five gases’ visible lines side by side: each pattern is a fingerprint. Choose one to see it in detail below.

Wavelength in nanometresA nanometre (nm) is a billionth of a metre. Our eyes see light from about 380 nm (violet) to 750 nm (red); a human hair is about 80,000 nm wide.
Neon spectral lines

Click a line to see where it comes from.

692.9 nmred

An electron falls from the 3p level down to the 3s level. It loses 1.79 eV of energyAn electronvolt (eV) is a tiny unit of energy used for atoms: the energy one electron gains crossing 1 volt. A particle of visible light carries between about 1.7 eV (red) and 3.3 eV (violet). and gives it off as one particle of red light. Bigger drops give bluer light.

Energy3p · 18.64 eV3s · 16.85 eV0 eV · ground

The strongest visible lines of neutral neon from the NIST Atomic Spectra Database. Line brightness follows NIST’s relative intensities, which only compare lines of the same element. Colours are approximate, and lamp colours are as they look to the eye.

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