Glass famously blocks what type of electromagnetic waves?

Glass famously blocks what type of electromagnetic waves?

• A. Radio waves
• B. Infrared
• C. Ultraviolet
• D. Gamma rays

Answer: (B)

This item tests how materials interact with different wavelengths of electromagnetic radiation. Glass is transparent to visible light, which is why we can see through it. But it blocks infrared radiation—heat energy—more than visible light, so infrared waves don’t pass through as easily. That’s why windows can feel warm to the touch from sunlight but still let us see inside. By contrast, radio waves largely pass through glass, ultraviolet light is mostly blocked by ordinary glass, and gamma rays can penetrate glass with only some attenuation. So the type of electromagnetic waves that glass famously blocks is infrared.

This item tests how materials interact with different wavelengths of electromagnetic radiation. Glass is transparent to visible light, which is why we can see through it. But it blocks infrared radiation—heat energy—more than visible light, so infrared waves don’t pass through as easily. That’s why windows can feel warm to the touch from sunlight but still let us see inside. By contrast, radio waves largely pass through glass, ultraviolet light is mostly blocked by ordinary glass, and gamma rays can penetrate glass with only some attenuation. So the type of electromagnetic waves that glass famously blocks is infrared.