Which gas-based lighting source is associated with greener color output?

Which gas-based lighting source is associated with greener color output?

• A. Sodium vapor
• B. Mercury vapor
• C. Neon
• D. LED

Answer: (B)

Gas-discharge lighting gets its color from the emission spectrum of the gas being excited. Each gas emits light at specific wavelengths, so the visible color is tied to those spectral lines. Sodium vapor lamps mainly emit a very bright yellow-orange light, so they aren’t green. Neon lamps glow in red-orange tones. Mercury vapor lamps, however, produce several lines in the blue-green region, with the strong green line around 546 nm giving a greenish hue. LED is not a gas-based technology, so it isn’t described by these gas spectra. So, the gas-based source associated with greener color output is mercury vapor, because its emission spectrum includes prominent greenish light.

Gas-discharge lighting gets its color from the emission spectrum of the gas being excited. Each gas emits light at specific wavelengths, so the visible color is tied to those spectral lines.

Sodium vapor lamps mainly emit a very bright yellow-orange light, so they aren’t green. Neon lamps glow in red-orange tones. Mercury vapor lamps, however, produce several lines in the blue-green region, with the strong green line around 546 nm giving a greenish hue. LED is not a gas-based technology, so it isn’t described by these gas spectra.

So, the gas-based source associated with greener color output is mercury vapor, because its emission spectrum includes prominent greenish light.