Which of the following is not true about X-rays?
A
Have low penetrating power
B
Travel with the speed of light
C
Can be reflected or refracted
D
Can affect photographic plates
Correct Answer: Have low penetrating power
X-rays and gamma rays are photons, i.e. high energy light-waves. When emitted by a source, for example, radium or cobalt, located outside the body, they easily pass through the body, hence they are usually called penetrating radiation. Because X-rays are penetrating, they can be used in diagnostic medicine to image human bones or human organs made opaque by a dye.