EM Waves & Matter Flashcards

All 4 cards in this deck

Name the four things a substance may do to an electromagnetic wave.

Absorb, transmit, refract or reflect it — and this varies with the wavelength of the wave.

What causes white light to split into colours when it crosses the boundary from air into glass?

The colours have different wavelengths and travel at different speeds in glass, so they refract by different amounts.

Why can a radio-wave remote control work from behind an armchair when an infrared one may not?

Infrared is absorbed/blocked by the armchair, while radio waves are transmitted through it, because they have different wavelengths.

True or false? UVA, UVB and UVC all pass through the Earth's atmosphere equally well.

False. The shorter the wavelength the more is absorbed — UVA is mostly transmitted and UVC is completely absorbed.