The table below shows a sample wavelength of each type of electromagnetic radiation, along with its frequency and energy.
Type
of EM
Radiation Sample
Wavelength
(cm) Frequency
(Hz) Energy
(electron-volts)
radio 150 2.0 × 108 8.3 × 10-7
microwave 1.0 3.0 × 1010 1.2 × 10-4
infrared 1.0 × 10-3 3.0 × 1013 0.12
Visible 5.0 × 10-5 6.0 × 1014 2.5
ultraviolet 5.0 × 10-6 6.0 × 1015 25
X-rays 1.0 × 10-8 3.0 × 1018 1.2 × 104
gamma
rays 1.0 × 10-10 3.0 × 1020 1.2 × 106
Because electromagnetic waves possess different wavelengths, frequencies, and energies, they are used for different purposes.
Radio waves, for example, can be used to transmit data, such as music and text messages. Microwaves are used to cook food, and infrared rays are used in night vision goggles.
On the other end of the spectrum, ultraviolet rays can affect vitamin D levels in humans, X-rays are used in medical imaging, and gamma rays are used in radiation cancer therapy.
Given this information, what type of electromagnetic waves are most likely the safest if one is exposed to them?
A.
waves with shorter wavelengths
B.
waves with higher frequencies
C.
higher amplitude waves
D.
lower energy waves