1. In pg 38 Fusion review
Create a double bubble map comparing and contrasting fission and fusion
Nuclear
Fission
Fusion

2. P1&4 Wed 9/23 p3&6 Thurs 9/24
Electromagnetic spectrum
That’s me!

3. The Electromagnetic Spectrum
Presentation for lesson 4: Exploring the Electromagnetic Spectrum, in the Waves: The Three Color Mystery unit
The slides are animated so you can click (space bar, mouse, etc.) to show the next item when the class is ready.
The Electromagnetic Spectrum
Watch the video by clicking on the title hyperlink.

4. Thru p 39
The Anatomy Of A Wave
Glue Wave diagram on p 39

5. Waves on the Ocean
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 324

6. Wavelength of a Wave l Wavelength () - length of one complete wave
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 324

7. Wavelength of a Wave l
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 324

8. Unplucked string 1 half-wavelengths 2 half-wavelengths
de Broglie also investigated why only certain orbits were allowed in Bohr’s model of the hydrogen atom.
• de Broglie hypothesized that the electron behaves like a standing wave, a wave that does not travel in space.
• Standing waves are used in music: the lowest-energy standing wave is the fundamental vibration, and higher-energy vibrations are overtones and have successively more nodes, points where the amplitude of the wave is zero.
• de Broglie stated that Bohr’s allowed orbits could be understood if the electron behaved like a standing circular wave. The standing wave could exist only if the circumference of the circle was an integral multiple of the wavelength causing constructive interference. Otherwise, the wave would be out of phase with itself on successive orbits and would cancel out, causing destructive interference.
2 half-wavelengths
3 half-wavelengths

9. Frequency
1 second
Frequency
4 cycles/second = 4 hertz
12 cycles/second = 12 hertz
36 cycles/second = 36 hertz
The energy of light is closely related to its color. High energy light appears purple, low energy light appears red, and intermediate energies of light have intermediate colors such as blue, green, yellow, and orange.
Higher frequency waves have more energy and are of a shorter wavelength.
In visible light, red light has the longest wavelength (lowest frequency) and blue/violet light has the shortest wavelength (highest frequency).
Frequency () - # of waves that pass a point during a certain time period
hertz (Hz) = 1/s
O’Connor, Davis, MacNab, McClellan, CHEMISTRY Experiments and Principles 1982, page 166

10. AM & FM Waves Carrier frequency Sound pattern
AM - FM Radio
Amplitude Modulated carrier
Frequency Modulated carrier

11. Waves Amplitude (A) - distance from the origin to the trough or crest
Low
frequency
High
Amplitude
long wavelength l
short wavelength l
Amplitude (A) - distance from the origin to the trough or crest

12. Waves Low frequency High frequency long wavelength l
Amplitude
Low
frequency
60 photons
162 photons
low energy
short wavelength l
Amplitude
Einstein‘s photons of light were individual packets of energy that had many characteristics of particles.
• Einstein’s hypothesis that energy is concentrated in localized bundles was in sharp contrast to the classical notion that energy is spread out uniformly in a wave.
High
frequency
high energy

13. The Electromagnetic Spectrum
Thru p:40
The Electromagnetic Spectrum
The EM spectrum is the ENTIRE range of EM waves in order of increasing frequency and decreasing wavelength.
As you go from left  right, the wavelengths get smaller and the frequencies get higher. This is an inverse relationship between wave size and frequency. (As one goes up, the other goes down.) This is because the speed of ALL EM waves is the speed of light (300,000 km/s).

14. The Electromagnetic Spectrum
HIGH
ENERGY
Decreasing wavelength
LOW
ENERGY
Increasing frequency
Increasing photon energy
AM radio
Short wave
radio
Television channels FM
Radar
Microwave
Radio Waves V i s b l e L g h t
Gamma Rays UV
Rays
“The Electromagnetic Spectrum”
Description: This slide depicts the electromagnetic spectrum from gamma rays through radio waves.
Basic Concepts
·         All forms of electromagnetic radiation are not identical
·         All forms of electromagnetic radiation travel at the same speed in a vacuum (the speed of light, c = 3.00 x 108 m/sec).
·         Wavelength and frequency are inversely proportional for a wave traveling at a constant speed.
·         Energy and frequency are directly proportional for electromagnetic waves traveling at the speed of light.
Teaching Suggestions
Use this transparency to review the relationship of visible light to other types of radiation. Explain that all of the rays and waves shown are types of electromagnetic radiation. Point out that they differ essentially from each other only in energy level, wavelength, and frequency. Try the analogy of an ocean wave to help students understand electromagnetic waves. Question 6 can be used to assess the students understanding of wave velocity, wavelength, and frequency.
Questions:
List the ways in which visible light is different from the other types of radiation shown in the diagram.
List the ways in which all of the types of radiation shown in the diagram are similar.
You are told that sound waves cannot travel in a vacuum. Are sound waves a types of electromagnetic radiation? Explain your logic.
Radio waves can go around an obstruction if the obstruction is smaller than the radio wave’s wavelength. What would you expect to happen if visible light were beamed at a thin wire 2 x 10-5 centimeter thick? Explain your answer.
For electromagnetic waves traveling at the speed of light, the wavelength is inversely proportional to frequency, as expressed by the equation c = fl, where c = speed of light in vacuum (3.00 x 108 meters/second), f = frequency, and l= wavelength. Using this equation, calculate the frequency of a 3-meter radio wave traveling at the speed of light. Compare your answer with the diagram.
Suppose that at a particular beach the ocean waves are traveling at a speed of 2 meters/second. If you know that the distance between waves is 10 meters, can you calculate how often they hit the shore? Explain your answer.
For electromagnetic waves traveling at the speed of light, the energy of a single photon is expressed by the equation E = hf, where E = energy, f = frequency, and h = Planck’s constant, 6.6 x joules/hertz.
Which has more energy, a photon of visible light or a photon of radar, if both traveling at the speed of light?
Do you think you can calculate the energy of an ocean wave using this energy equation? Explain your answer.
infrared
X- Rays
R O Y G B I V
Red Orange Yellow Green Blue Indigo Violet

15. Things to Remember
The higher the frequency, the more energy the wave has.
EM waves do not require media in which to travel or move.
EM waves are considered to be transverse waves because they are made of vibrating electric and magnetic fields at right angles to each other, and to the direction the waves are traveling.
Inverse relationship between wave size and frequency: as wavelengths get smaller, frequencies get higher.
Play an interactive tutorial to explore the classical representation of an electromagnetic wave as a sine function; you can vary amplitude and wavelength to demonstrate how this function appears in three dimensions. (requires java plug-in) See:

16. The Waves (in order…)
Radio waves: Have the longest wavelengths and the lowest frequencies; wavelengths range from 1000s of meters to .001 m
Used in: RADAR, cooking food, satellite transmissions

17. Radio waves Longest wavelength EM waves Uses: TV broadcasting
AM and FM broadcast radio
Heart rate monitors
Cell phone communication
MRI (MAGNETIC RESONACE IMAGING)
Uses Short wave radio waves with a magnet to create an image
Click the little rainbow box in the top right corner to return to the overview EM spectrum diagram

18. Microwaves: Slightly shorter wavelengths and higher frequencies; Wavelengths from 1 mm- 1 m
Uses:
Microwave ovens
Bluetooth headsets
Broadband Wireless Internet
Radar
GPS
Click the little rainbow box in the top right corner to return to the overview EM spectrum diagram

19. Infrared waves (heat): Have a shorter wavelength, from
Infrared waves (heat): Have a shorter wavelength, from .001 m to 700 nm, and therefore, a higher frequency. Wavelengths in between microwaves and visible light
Uses:
Night vision goggles
Remote controls
Heat-seeking missiles
Click the little rainbow box in the top right corner to return to the overview EM spectrum diagram

20. Only type of EM wave able to be detected by the human eye
Visible light: Wavelengths are shorter (from 700 nm -red light- to 30 nm -violet light) and frequencies higher than infrared waves.
Only type of EM wave able to be detected by the human eye
Visible light waves are a very small part of the EM spectrum!
Violet is the highest frequency light
Red light is the lowest frequency light
Click the little rainbow box in the top right corner to return to the overview EM spectrum diagram

21. Visible Light Remembering the Order
ROY G. BV
red
orange
yellow
green
blue
violet
Light from the sun looks white, but it is really made up of all the colors of the rainbow. A prism is a specially shaped crystal. When white light shines through a prism, the light is separated into all its colors.

22. Ultraviolet Light: Wavelengths range from 400 nm to 10 nm; the frequency (and therefore the energy) is high enough with UV rays to penetrate living cells and cause them damage.
Although we cannot see UV light, bees, bats, butterflies, some small rodents and birds can.
UV on our skin produces vitamin D in our bodies. Too much UV can lead to sunburn and skin cancer. UV rays are easily blocked by clothing.

23. Ultraviolet Uses: Shorter wavelengths than visible light Black lights
Security images on money
Harmful to living things
Used to sterilize medical equipment because they kill bacteria.
Extremely high exposure can cause skin cancer
There is one more UV slide…

24. X-Rays: Tiny wavelength, high energy waves. Wavelengths from 10 nm to
X-Rays: Tiny wavelength, high energy waves. Wavelengths from 10 nm to .001 nm.
These rays have enough energy to penetrate deep into tissues and cause damage to cells; are stopped by dense materials, such as bone.
Used to look at solid structures, such as bones and bridges (for cracks), and for treatment of cancer.

25. X-rays Uses: Medical imaging Airport security
Moderate dose can be damaging to cells
Click the little rainbow box in the top right corner to return to the overview EM spectrum diagram

26. Gamma Rays: Carry the highest energy and have the shortest wavelengths, less than one trillionth of a meter (10-12).
Gamma rays have enough energy to go through most materials easily; you would need a 3-4 ft thick concrete wall to stop them!
Gamma rays are released by nuclear reactions in nuclear power plants, by nuclear bombs, and by naturally occurring elements on Earth.

27. Gamma Rays Uses Smallest wavelengths, highest energy EM waves
Sometimes used in the treatment of cancers. Too much exposure can cause cancer!
Sterilizes medical equipment
Cancer treatment to kill cancer cells
Kills nearly all living cells.
Click the little rainbow box in the top right corner to return to the overview EM spectrum diagram

28. Gamma Rays
This picture is a “scintigram” 
It shows an asthmatic person’s lungs.
The patient was given a slightly radioactive gas to breath, and the picture was taken using a gamma camera to detect the radiation.
The colors show the air flow in the lungs.

29. Image Sources
Micro Worlds, Lawrence Berkeley National Laboratory.
2004 Microsoft Corporation, One Microsoft Way, Redmond, WA USA.
NASA
NASA
NASA
Andy Darvill, Broadoak Community School, Radioactivity Uses

30. Thru p41 Create your own EM spectrum
Using materials provided, cut out and glue each part of the EM spectrum in the proper order according to the information in your notes.

31. Out p38 What wave has the highest frequency?
What are the wavelengths called that humans can see?