All of the options A, B, C, and D are common among electromagnetic waves. Let's go through each option:
A. Energy: Electromagnetic waves carry energy. The energy of an electromagnetic wave is proportional to its intensity, which is determined by the amplitude of the wave.
B. Frequency: Electromagnetic waves have a frequency associated with them. Frequency refers to the number of wave cycles or oscillations that occur in a given time. Electromagnetic waves with higher frequencies have more oscillations per unit time and are associated with higher energy.
C. Speed in vacuum: Electromagnetic waves all travel at the same speed in a vacuum, which is approximately 299,792,458 meters per second (often rounded to 3.00 x 10^8 m/s). This speed is commonly denoted by the symbol "c" and is known as the speed of light.
D. Wavelength: Electromagnetic waves have a characteristic wavelength. Wavelength refers to the distance between two consecutive points of the wave that are in phase (e.g., two peaks or two troughs). It is typically denoted by the Greek letter lambda (λ). Wavelength and frequency are inversely related; as the frequency increases, the wavelength decreases, and vice versa.
In summary, energy, frequency, speed in vacuum, and wavelength are all common properties of electromagnetic waves.