Which statement correctly describes the speed of x-rays?

Which statement correctly describes the speed of x-rays?

• A. X-rays travel faster than light.
• B. X-rays travel at the speed of light.
• C. X-rays travel slower than light in a vacuum.
• D. X-ray speed varies with energy.

Answer: (B)

All electromagnetic radiation travels at the speed of light in a vacuum, and X-rays are electromagnetic waves. This speed is a constant for all wavelengths in vacuum, about 3.00 x 10^8 meters per second, and it isn’t affected by the X-ray’s energy. In a material, the speed can be reduced depending on the medium’s refractive index, but in empty space X-rays travel at the speed of light. That’s why the correct statement is that X-rays travel at the speed of light. The other options describe faster-than-light travel, slower-than-light travel in vacuum, or speed varying with energy in vacuum, which aren’t accurate.

All electromagnetic radiation travels at the speed of light in a vacuum, and X-rays are electromagnetic waves. This speed is a constant for all wavelengths in vacuum, about 3.00 x 10^8 meters per second, and it isn’t affected by the X-ray’s energy. In a material, the speed can be reduced depending on the medium’s refractive index, but in empty space X-rays travel at the speed of light. That’s why the correct statement is that X-rays travel at the speed of light. The other options describe faster-than-light travel, slower-than-light travel in vacuum, or speed varying with energy in vacuum, which aren’t accurate.