Which property does not pertain to light?

Which property does not pertain to light?

• A. Mass
• B. Reflection
• C. Speed
• D. Refraction

Answer: (A)

Light behaves in ways we can observe and measure, such as reflecting off surfaces, traveling at a certain speed, and bending when it enters a different medium. A key idea is that light is massless in the sense of rest mass: photons carry energy and momentum, but they do not have rest mass. That means mass is not a characteristic we use to describe light. The speed of light in a vacuum is a constant, and when light enters another medium its speed changes, causing refraction or bending. Reflection is the light bouncing off a surface. Since these are familiar behaviors of light, those options describe light, while mass does not pertain to light.

Light behaves in ways we can observe and measure, such as reflecting off surfaces, traveling at a certain speed, and bending when it enters a different medium. A key idea is that light is massless in the sense of rest mass: photons carry energy and momentum, but they do not have rest mass. That means mass is not a characteristic we use to describe light. The speed of light in a vacuum is a constant, and when light enters another medium its speed changes, causing refraction or bending. Reflection is the light bouncing off a surface. Since these are familiar behaviors of light, those options describe light, while mass does not pertain to light.