The Electromagnetic Spectrum
The electromagnetic spectrum shows the different types of electromagnetic radiation arranged by wavelength, from gamma rays with very short wavelengths (in the picometer range) to radio waves with very long wavelengths (from about 1 meter to many kilometers in length).
Wavelength and frequency are inversely proportional. Long-wavelength radiation has low frequency, and short-wavelength radiation has high frequency. As frequency increases, the energy of a photon of that radiation increases as well — so as wavelength increases, photon energy decreases.
The Equations
c = λν
c = speed of light, 2.998 × 108 m/s
λ = wavelength in meters (m)
ν = frequency in hertz (s-1)
λ = wavelength in meters (m)
ν = frequency in hertz (s-1)
Ephoton = hν
ν = frequency in hertz (s-1)
h = Planck's constant, 6.626 × 10-34 J·s
h = Planck's constant, 6.626 × 10-34 J·s
As frequency ↑, photon energy ↑
As wavelength ↑, frequency and photon energy ↓ (and vice versa). You can reopen these equations any time during practice.
This module has three levels: Level 1 orders regions of the spectrum by wavelength, frequency, or energy. Level 2 compares two examples of radiation. Level 3 asks you to calculate one property from another.