Electromagnetic Spectrum – Key Terms (from lecture notes)

Vocabulary flashcards covering key terms and concepts from the electromagnetic spectrum as presented in the notes.

Radio waves

Wavelengths from 1 nm to 100 m; excite spin of nucleus (MRI, non-invasive); used for AM/FM radio.

Microwaves

Wavelengths from 100 μm to 100 cm; excite spin of electrons; rotate/motion of H2O and fats; used for cooking (around 12 cm).

Infrared

Wavelengths from 800 to 1000 nm (about 1 μm); causes molecular vibrations; used in night vision goggles; used to measure intoxication via OH in ethanol.

Visible light

Wavelengths from 300 to 800 nm; excites valence electrons to higher energy levels; relates to Balmer series and human eye detection.

Balmer series

Hydrogen emission lines in the visible region (transitions to n=2).

Ultraviolet

Wavelengths from 300 to 10 nm; includes Lyman series (H) of ultraviolet emission; causes sunburn; exposure can cause cell mutations.

X-rays

Wavelengths from 10 to 0.01 nm; excite core and valence electrons; used in invasive imaging; high exposure can cause mutations; exposure should be limited.

Gamma rays

Wavelengths shorter than about 0.01 nm; high-energy photons produced by nuclear decay.

Cosmic rays

High-energy radiation originating from space (often associated with stars); name derives from their cosmic origin.

Lyman series

Hydrogen ultraviolet emission lines from transitions to n=1; part of UV spectrum.