Question

The major difference between X-rays and visible light is:

• A. X-rays have a shorter wavelength and higher energy
• B. X-rays travel slower than light
• C. X-rays are not electromagnetic waves
• D. X-rays carry an electric charge

Hint:

Both are electromagnetic and travel at light speed, so look at wavelength and energy.

Answer 1

The Correct Option is A

Step 1: Both X-rays and visible light are electromagnetic radiation, so they share several properties: both are uncharged, both travel at the speed of light in vacuum, and both are part of the same electromagnetic spectrum.
Step 2: The features they share rule out three options at once. X-rays do travel at the speed of light, so they are not slower. They are electromagnetic waves, so they are not non-electromagnetic. They carry no charge, just like light.
Step 3: What truly separates them is wavelength and therefore photon energy. Visible light has wavelengths of roughly 400 to 700 nanometres, while X-rays have wavelengths around 0.01 to 10 nanometres, which is thousands of times shorter.
Step 4: Because photon energy is inversely related to wavelength through \(E = hc/\lambda\), the very short wavelength of X-rays gives them much higher photon energy. This high energy is why X-rays can ionize atoms and penetrate tissue, while visible light cannot.
Step 5: So the major difference is that X-rays have a much shorter wavelength and far higher energy.
Answer: Option A.