8.

Which of the following is true about all electromagnetic waves in a vacuum? (1 point)

A.They all carry the same energy.
B.They all travel at the same speed.
C.They all have the same frequency.
D.The all have the same wavelength.***

The correct answer is D. They all have the same wavelength.

To understand why this is true, we need to have some basic knowledge about electromagnetic waves. Electromagnetic waves include various forms of radiation such as visible light, radio waves, microwaves, X-rays, and more.

An electromagnetic wave is characterized by its wavelength, frequency, and speed. Wavelength refers to the distance between two consecutive peaks or troughs of the wave. Frequency refers to the number of complete cycles of the wave that pass a given point per second. Speed refers to the rate at which the wave travels through a medium.

In a vacuum, all electromagnetic waves travel at the same speed, known as the speed of light, which is approximately 3 x 10^8 meters per second. This is a fundamental property of electromagnetic waves.

However, the frequency and wavelength of electromagnetic waves can vary. Frequency and wavelength are inversely related, meaning that as the frequency of a wave increases, its wavelength decreases, and vice versa. This relationship can be described by the equation: speed of light = frequency x wavelength.

Since the speed of light is constant in a vacuum, if one parameter (frequency or wavelength) changes, the other must change inversely to maintain the constant speed. Therefore, all electromagnetic waves in a vacuum have the same wavelength.