Answer:
Frequency, wavelength or photon energies.
Ionizing radiation
Visible radiation
Micro-waves and radio waves
Explanation:
The electromagnetic radiation spectrum is categorized on the basis of frequency, wavelength or photon energies. The electromagnetic spectrum arranges the radiation into descending order of frequency, ascending order of wavelength or descending order of photon energies. The frequency range is from 300 EHz to 3 Hz. The wavelength range is from 1 pm to 100000 km. The photon energy range is from 1.24 MeV to 12.4 feV.
The main categories are:
Ionizing radiation: Gamma rays (300 EHz) to Extreme ultraviolet (30 PHz).
Visible radiation: Near ultraviolet (3 PHz) to Far infrared (20 THz).
Micro-waves and radio waves: Extremely high frequency (300 GHz) to Extremely low frequency (3 Hz).
