Electromagnetic Radiation and Light Ms. Chapo 7th Grade Science LaVilla School of the Arts

GOAL – page 12 I CAN recognize the order of the EM spectrum based on wave frequency and their common uses.

Lets recap stuff about EM waves… They do NOT need a medium to travel They only travel through transverse waves The Sun is a major source of EM waves

What is radiation? Radiation is the transfer of energy as EM waves.

What is in the EM spectrum? There are 7 EM waves that are part of the spectrum: RADIO WAVES MICROWAVES INFRARED LIGHT VISIBLE LIGHT ULTRAVIOLET LIGHT (UV) X-RAYS GAMMA RAYS

DRAW THIS!

Can you make your OWN pneumonic? V- U- X- G-

Types of EM radiation MAKE A 2 COLUMN CHART LIKE THIS: TYPE OF EM RADIATION USES RADIOWAVES MICROWAVES INFRARED LIGHT VISIBLE LIGHT UV LIGHT X-RAYS GAMMA RAYS

Types of EM radiation ANSWER KEY: TYPE OF EM RADIATION USES RADIOWAVES Radio and TV MICROWAVES Cooking, radar, TV, other INFRARED LIGHT HEAT from sun, fires, radiators VISIBLE LIGHT Things can be seen UV LIGHT Absorbed by skin, florescent tubes X-RAYS See inside of bodies GAMMA RAYS Medical treatment (kills cells)

What about the SUN? The Sun gives off mostly visible light, but gives off radiation in ALL areas of the EM spectrum!

How much is too much radiation? - The HIGHER the frequency, the MORE ENERGY that wave has = more dangerous. Like UV rays and gamma rays Gamma rays kill cancer cells The LOWER is frequency, the LESS ENERGY that wave has = less dangerous. like radio waves, microwave, infrared, visible light

NEW GOAL – page 14 I CAN identify the order of colors on the visible spectrum based on wave frequency and how colors are viewed.

VISIBLE LIGHT IS THE ONLY PART OF THE EM SPECTRUM HUMANS CAN SEE!

What are all of those colors again?? Red Orange Yellow Green Blue Indigo Violet

The longest wavelength = RED The shortest wavelength = VIOLET What determines the color of light? FREQUENCY! The longest wavelength = RED The shortest wavelength = VIOLET

How do we see white or black? When we see WHITE… ALL colors of ROYGBIV are reflected When we see BLACK… ALL colors of ROYBGIV are absorbed

Exit ticket Why do we see a tree frog as the color green?