Which statement about x-ray characteristics is NOT true?

Which statement about x-ray characteristics is NOT true?

• A. X-rays travel in straight lines
• B. They are not visible to senses
• C. They can be easily deflected
• D. They travel at half the speed of light

Answer: (D)

X-rays are electromagnetic waves that propagate at the speed of light. In practice, they move through air or soft tissues essentially at c and travel in straight lines until they encounter matter. They are invisible to our senses, which is why detectors and film are needed to image them. They can be deflected or scattered when they interact with matter, which is part of how imaging and exposure considerations arise. The statement that they travel at half the speed of light is not true; their speed is effectively the speed of light, not slower.

X-rays are electromagnetic waves that propagate at the speed of light. In practice, they move through air or soft tissues essentially at c and travel in straight lines until they encounter matter. They are invisible to our senses, which is why detectors and film are needed to image them. They can be deflected or scattered when they interact with matter, which is part of how imaging and exposure considerations arise. The statement that they travel at half the speed of light is not true; their speed is effectively the speed of light, not slower.