Note-taking Guide

1. Note-taking Guide • We’re about to watch a presentation prepared by two former students and edited by Mr. McCall. • To prepare your notebook, everyone has been given two extra pages. Tape them into your notebook as directed

2. Tape the pages into your notebook

4. Harissa Massoud & Mikiah Olson

6. Words You Need to Know - • Angstrom- an angstrom is a unit of length that is equal one ten billionth of a meter. Your fingernails grew about 100 angstroms in the time it took you to read this! • Dispersion- allows us to see the mixture of wavelengths in light

7. Rabbits Multiply In Very Unusual eXpensive Gardens. • Rabbits – Radio waves • Multiply – Microwaves • In – Infrared waves • Very – Visual light • Unusual – Ultraviolet Waves • eXpensive – X-rays • Gardens – Gamma rays

8. What is the Electromagnetic Spectrum? • The Electromagnetic Spectrum has nothing to do with magnets, like the kind you put on the fridge, instead it is ; • a continuous spectrum that ranges from the lowest frequency to the highest, beginning with radio waves, all the way up to gamma rays, which, have a wavelength of 0.001 angstrom. This is very small in comparison to long waves which have a wavelength of more than one million km.

9. Image credit: Wikimedia commons http://en.wikipedia.org/wiki/File:EM_Spectrum_Properties_edit.svg#file

10. What is the Electromagnetic Spectrum, (cont.,) • Scientists have found that many types of waves can be arranged like notes on the piano. • ‘Low Notes’ – low frequency and long wavelength • ‘High Notes’ – high frequency and short wavelength

11. Radio Waves • Radio waves can be made by various types of transmitters depending on the wavelength, which is the longest of the entire spectrum. • What most don’t know is that this can also be created by stars, sparks, and lightning. (You hear the interference during a thunder storm).

12. Types of Radio Waves - • Radio waves are used in radios, TVs, military communication, cell phones, ham radios and others. They are what give us the sound that we jam out to in our car, the “reception,” on our cell phones, and the picture on the TV, the ease of communications.

13. Microwaves • Microwaves are the higher frequency radio waves, but are actually low frequency on the entire spectrum, and most often made by transmitters. • The wavelength is a couple of centimeters, and is used in cell phones, transmitter chips, antennas, and in microwaves ovens.

14. Infra Red Light “IR” • Infra red is just below visible red light, and is given off by WARMobjects, such as stars, lamps, flames, you or me, anything that gives off heat. • Used in – remotes for the TV, heal sports injuries, mobile phones, alarm systems, and weather forecasters use them for cloud and rain patterns. • Infra-Red Waves are a millionth of a meter in wavelength.

15. Visible Light • Visible light is what our own eyes can see – like light bulbs. And just because you can see it, doesn’t mean you should STARE at it. • It’s made by light HOT enough to glow, like fire and the sun - it all involves HEAT. • For instance, light bulbs use an electric current to heat a lamp filament to around 3,000 degrees to make it glow white hot. And don’t touch it to see if it’s really that hot. • The sun is obviously a giant ball of fire, and therefore it gives off a lot of light.

16. Visible Light, cont., • White light is actually ALL colors mixed together. You can prove this by using a glass prism. (This is called dispersion) • Weird enough, we use light to see things! • Light waves can also be made using a laser. • The Wavelength is 400nm. • WARNING- to much light can damage the retina in your eyes. (the retina is the layer of nerves in the back of your eye)

17. Ultra Violet Light • Ultra-Violet light is commonly referred to as “UV” You hear about this in sunblock ads, and when you hear about the ozone layer. • Ultra Violet Light is given off in large quantities by the sun. The lights in tanning beds also give off certain wavelengths of untraviolet

18. “UV” Rays Continued… • Its many uses include; • Bug Zappers • Tanning Beds • Detecting Fake Money • “Blacklights”that make your clothes glow • UV is also used in labs and hospitals to kill microbes and sterilize surfaces.

19. X-Rays • X-Rays are very high frequency waves that carry a lot of energy. They are give off by stars and also by some typed of nebula. • The most commonly known use is through an X-Ray machine used to see bones. Doctors use them to see inside people . The rays easily passes through the soft tissue but reflect off of the bones. (That’s how it works). • They are also used through airport security checks and by astronomers. • By lowering its energy, you can see soft tissues like your brain. • They have a wavelength between 10 and 0.01 nanometers.

20. Gamma Rays • Gamma Rays are EXTREMELY high frequency waves, and they carry a large amount of energy. • They are given of by stars and other radioactive substances. • The pass through most materials and are hard to stop. (Though they can be stopped through the means of lead or concrete). • Because Gamma rays can kill living cells , they are used to kill cancer cells. This is called Radiotherapy. • They are also used in sterilization. • They can cause cell damage and cancer. • They can also cause mutations in growing tissues. (See the HULK)… and no, mutations don’t really work like that!

21. To Conclude…….. The wavelengths that we’ve discussed are; • Radio Waves • Microwaves • Infra Red • Visible Light • Ultra Violet • X-Rays • Gamma Rays