Post on 01-Jan-2016
transcript
Create a double bubble map comparing and contrasting fission and fusion
NuclearFission
NuclearFusion
In pg 38Fusion review
P1&4 Wed 9/23p3&6 Thurs 9/24
• Electromagnetic spectrum• That’s me!
The Electromagnetic Spectrum
Watch the video by clicking on the title hyperlink.
Thru p 39The Anatomy Of A Wave
Glue Wave diagram on p 39
Waves on the Ocean
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 324
Wavelength of a Wave
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 324
l
• Wavelength () - length of one complete wave
Wavelength of a Wave
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 324
l
2 half-wavelengths
3 half-wavelengths
1 half-wavelengths
Unplucked string
Frequency
O’Connor, Davis, MacNab, McClellan, CHEMISTRY Experiments and Principles 1982, page 166
1 second
Frequency
4 cycles/second = 4 hertz
12 cycles/second = 12 hertz
36 cycles/second = 36 hertz
• Frequency () - # of waves that pass a point during a certain time period– hertz (Hz) = 1/s
AM & FM WavesCarrier frequency
Sound pattern
Amplitude Modulated carrier
Frequency Modulated carrier
AM - FM Radio
Waves
Low frequency
High frequency
Amplitude
Amplitude
long wavelength l
short wavelength l
• Amplitude (A) - distance from the origin to the trough or crest
Waves
Low frequency
High frequency
Amplitude
Amplitude
long wavelength l
short wavelength l
60 photons
162 photons
low energy
high energy
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).
Thru p:40
The Electromagnetic Spectrum
AM radio
Short waveradio
Television channels
FM radio
RadarMicrowave
Radio Waves Gamma Rays
X- Raysinfrared
Increasing photon energy
Increasing frequency
Decreasing wavelength
Red Orange Yellow Green Blue Indigo Violet
UV Rays
Visible
Light
R O Y G B I V
HIGH
ENERGY
LOW
ENERGY
Things to RememberThe 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.
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
The Waves (in order…)
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
• Microwaves: Slightly shorter wavelengths and higher frequencies; Wavelengths from 1 mm- 1 m
• Uses:– Microwave ovens– Bluetooth headsets– Broadband Wireless Internet– Radar– GPS
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
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 eyeVisible light waves are a very small part of the EM spectrum!
Violet is the highest frequency lightRed light is the lowest frequency light
ROY G. BVredorangeyellowgreenblueviolet
Visible LightRemembering the Order
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.
Ultraviolet• Shorter wavelengths than visible light• Uses:
– 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
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.
X-rays
• Uses:– Medical imaging– Airport security
• Moderate dose can be damaging to cells
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.
Gamma RaysSmallest wavelengths, highest energy EM wavesUses
Sometimes used in the treatment of cancers. Too much exposure can cause cancer!
Sterilizes medical equipmentCancer treatment to kill cancer cells
Kills nearly all living cells.
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.
Micro Worlds, Lawrence Berkeley National Laboratory. http://www.lbl.gov/MicroWorlds/ALSTool/EMSpec/EMSpec2.html
Image Sources
NASA http://spaceplace.nasa.gov/blue-sky/
NASA http://science-edu.larc.nasa.gov/EDDOCS/Wavelengths_for_Colors.html
NASA http://missionscience.nasa.gov/ems/11_xrays.html
Andy Darvill, Broadoak Community School, Radioactivity Uses
http://www.northallertoncoll.org.uk/science/Additional%20Physics/Nuclear/Nuclear/Radioactivity/uses.htm
2004 Microsoft Corporation, One Microsoft Way, Redmond, WA 98052-6399 USA.
Thru p41Create 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.
https://phet.colorado.edu/sims/html/molecules-and-light/latest/molecules-and-light_en.html
Out p38
1. What wave has the highest frequency?
2. What are the wavelengths called that humans can see?