Unit 2 Optics

Chapter 4 Many properties of light can be understood using a wave model of light.

4.3 Light and the Electromagnetic Spectrum


4.3 Introduction page 152

Invisible Waves

Invisible waves are all around us. For example, a rainbow is a visible spectrum, it is a tiny portion of a larger spectrum of radiation called a electromagnetic spectrum. Some examples of these "waves" are the sun's rays, a wireless internet connection, the microwave, television and radio frequencies. You can not feel or see these waves but they are traveling through our bodies. These invisible "waves" are helpful for communication and can help humans in many ways.

Questions:
Answers:
What is a tiny portion of a much larger spectrum of radiation(the electromagnetic spectrem) called?
Electromagnetic spectrum.


What has shorter wavelengths, higher frequencies, and more energy than visible light?
Ultraviolet light, X rays, and gamma rays.


What has longer wavelengths, lower frequencies, and less energy than visible light?
Radio Waves and visible light.


Each region of the invisible spectrum has special properties that make it useful in some sort of ?
Imaging tochnology.


Can you feel waves?
No


Can waves go through your body?
yes


Name 3 objects that use invisible waves
Sun waves, music waves, cellphone


How many types of sunscreen are there?
Tow types of sunscreen.


Name the types of sunscreen and what they do?
Physical sunscreens: protect the skin by reflecting the ultraviolet waves.
Chemical sunscreens: protect the skin by obsorbing the ultraviolet waves.