Unit 2: Waves. Electromagnetic Spectrum.
Electromagnetic Spectrum: The entire range of
electromagnetic waves.
https://education-portal.com/academy/lesson/the-7-major-regions-of-the-electromagnetic-spectrum.html#lesson
Unit 2: Waves. Electromagnetic Spectrum.
Fun Fact
Image: Klaus Schmitt
The petals on the flower look solid yellow to you but a bee may see dark
ultraviolet markings that make the same flower appear quite different
to the bee.
Unit 2: Waves. Electromagnetic Spectrum.
All EM waves travel at the same speed: 300 000 000 m/s
The waves are arranged from longest to shortest
wavelength
**As wavelength decreases the frequency increases**
Unit 2: Waves. Electromagnetic Spectrum.
Radio waves
have some of the
longest wavelengths
and lowest
frequencies. They are
the lowest energy
waves. This makes
them the safest.
TV signals are carried
by radio waves too.
Unit 2: Waves. Electromagnetic Spectrum.
Microwaves: have shorter wavelengths and higher
frequencies than radio waves.
Microwaves are used in radar and in monitoring the
movement of ships and airplanes.
Unit 2: Waves. Electromagnetic Spectrum.
Infrared Waves
These waves heat the Earth’s surface.
Warmer objects give off more infrared radiation
than cooler objects
Unit 2: Waves. Electromagnetic Spectrum.
Let’s stop and think…
How do infrared waves differ
from radio waves in terms of
frequency and wavelength?
Unit 2: Waves. Electromagnetic Spectrum.
Visible Light: the narrow range of wavelengths
and frequencies in the EM spectrum that
humans can see.
Red light: Longest wavelengths
Violet light : Shortest wavelengths (higher energy)
Unit 2: Waves. Electromagnetic Spectrum.
Ultraviolet Light
Positive Effects of UV light
•Artificially produced to kill
bacteria on food and surgical
instruments
•Limited exposure to UV in the sun
produces vitamin D
Negative Effects of UV light
•Sunburn
•Skin cancer
•Damage to the eyes
•Wrinkles
•Premature aging of the skin
Unit 2: Waves. Electromagnetic Spectrum.
X Rays: Carry a great deal
of energy, allowing them
to penetrate a variety of
materials.
Too much exposure can
damage or kill living cells.
Unit 2: Waves. Electromagnetic Spectrum.
Gamma Rays: Have the most energy
(+) Used to treat some forms of cancer.
(-) Produced during nuclear reactions.
Unit 2: Waves.
Ticket Out the Door…
1. How are wavelength and frequency related?
2. How is the electromagnetic spectrum
arranged?
3. Which type of light has the longest
wavelength in the electromagnetic
spectrum?