1. Ch 18-2 Electromagnetic Spectrum

2. Waves of the Spectrum
• Waves beyond the visible red end of the color band
is called infrared radiation.
• The full range of frequencies is the electromagnetic
spectrum.
• The spectrum includes many types of waves

3. Radio Waves
• They are used in radio, television, radar and
microwave ovens.
• Radios use 2 ways Amplitude modulation and
frequency modulation.
• Microwaves are shortest radio waves (1m – 1mm)
• Used in cell phones and to cook food
• Radar is used to determine location and
speed of objects

4. Other rays
• Infrared rays - have lower frequencies than light
(1mm – 750nm) it is used to discover areas of heat
differences.
• Visible Light – helps people to see and use colors.
• Ultraviolet rays – higher frequency than light, it is
used in medicine and agriculture. Helps your body
produce Vitamin D. Lamps made to mimic the sun

5. Other Rays
• X – Rays – high frequency and high energy
which can penetrate matter that light cannot.
It is used to take pictures of solid objects.
• Gamma Rays – the shortest wavelengths
and highest frequencies in the spectrum so
they have the most energy. Used to kill
cancer cells, take pics of the brain it is
dangerous to people if over exposed.