Can you guess how
electromagnetic waves got
their name? They consist of
both electric and magnetic
forces produced when electric
charges move up & down.
Like ocean waves,
electromagnetic waves have
crests and troughs. The
distance between one crest
and the next is the
wavelength.

Electromagnetic
Waves - Length
Radio Waves - 1 to 10,000 meters
Microwaves - 0.001 to 1 meter
Infrared - 0.000001 to 0.001 meter
Visible Light - 400 to 800 nanometers
Ultra violet - 10 to 400 nanometers*
X rays - 0.0001 to 10 nanometers*
Gamma Rays - 0.1 to 0.0000001 nanometer*
*1 nanometer =0.000000001 meter

Electromagnetic waves exist
in many different lengths,
from very long to extremely
short Radio waves, for
example, are sometimes as
long as 10,000 meters. On
the other hand, gamma rays,
the smallest electromagnetic waves. They are only trillionths of a meter.
Below is a table that shows the lengths of electromagnetic waves. Notice that microwaves are among
the electromagnetic waves listed in the table. Microwaves are used in items such as television.
equipment and ovens. The microwaves used in these items aren't captured from the atmosphere or
outer space. They are produced electronically.

1. If an electromagnetic wave, from crest to crest, measured 30 nanometers, what kind of wave would
it be?
2. Convert 400 nanometers to meters? (Hint: 1 nanometer = 0.000000001 meter)

3. Why do you think ultraviolet and visible light waves are usually measured in units of
nanometers rather than meters or centimeters?

4. Look at the electromagnetic spectrum in your notes/slides/textbook. Notice that it shows
wavelengths measured using scientific notation. How many meters long is a wavelength
that measures 10²m.

5. If a wavelength measures 1 nanometer, how would you write this in scientific
notation?