Light and the Electromagnetic Spectrum
What is light?
 Light is a form of energy that you can detect with your eyes
 Light energy comes from other forms of energy
o _________________________________________
 Natural light --> Naturally made (sun)
 Artificial light--> produced by humans (candles, light bulbs)
 Objects that emit (give off) their own light are said to be
___________

Sun
Switched on flashlight
 Objects that do not emit light are said to be _____________
o When flashlight is switched off, the moon
Light from the Sun
 ________________________________
When hydrogen atoms in the Sun’s core collide, they sometimes
combine to form helium (________________)
Fusion reaction --> releases a lot of energy. This energy
from energized atoms is released in the form of light
Properties of Light
 _______________________________________________
_________________
 Light travels so fast ~ 7.5 times around the equator in 1s
 Light travels at a speed of ________________ but has
different wavelengths
Electromagnetic Spectrum – is a diagram that illustrates the range
of electromagnetic waves, in order of frequency
 The visible colours of light are just different wavelengths of
light
 White light splits up into visible colours (ROYGBV)
 Violet has the shortest wavelength of visible light
 We cannot see UV radiation from the sun but we still get sun
burnt
 We use microwaves to cook food
 Radio waves carry signals to our tvs/radios
 X-rays produce images of internal organs
Type of Radiation
Radio
Microwaves
Infrared
Visible light
Frequency, energy
level and wavelength
(high/low,
short/long)
Provide 2 examples
Explanation
Energy from radio
stations/tvs emit
into the air from
your ipod and turn
into your favourite
song
They will cook your
popcorn!
Our skin emits
infrared light. This
is why we can be
seen in the dark by
vision goggles
Theis is the part
our eyes can see
UV
Sun is the major
source
X-Rays
Your doctor uses
them to look at your
bones
Gamma Rays
Radioactive and
nuclear plants
Learning Check:
The following diagrams represent six types of electromagnetic radiation. Match the
diagram with the following names: radio, x-rays, red light, microwave, violet light,
ultraviolet
wavelength