Lesson plan 3 Monday[ 9821] PDF

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Download Lesson plan 3 Monday[ 9821] PDF

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CHEM 1A - Week 3 Monday (October 14, 2019) Lesson Plan for Professor Arasasingham with LARC Leader: Shania Day

LEARNING GOAL: Students will be able to solve Electromagnetic Radiation problems and problems about the Wave Nature of Matter by working in groups to find the answers while getting familiar with using their scientific calculators. 

ICEBREAKER: 1. Take about 5 minutes to find 2 things each of you have in common with each other in your table groups. Once the 5 minutes are up you will present each other to the class.

Guided Practice: 1. 

1 

Behavior of Waves

Electromagnetic Radiation

Wave - Particle Duality of Electromagnetic Radiation

1. Reflection: change in direction of wave when it bounces off a barrier and goes in a new direction within the same medium 

1. Energy that travels through electromagnetic waves and empty space  2. Does not require a medium for transmission like air or water

Theory that electromagnetic radiation has wave and particle-like properties  1. Means that light can also exhibit

2. Refraction: change in direction of wave as it passes into and through a new medium  3. Diffraction: bending of the wave around a corner of a barrier or through holes in the barrier  4. Interference:  Constructive Interference when 2 waves are in phase and have the same properties making them additive Vs. Destructive Interference when 2 waves are out of phase and their properties are offset making them not additive  

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2 

 3. Has both electric and magnetic field  Speed of transport energy/ speed of light constant (c) = 3.00 x 10^8 m/s  Speed of electromagnetic wave = c = ν ( λ) in m/s

properties of waves or particles but never both at the same time  Wave-particle Duality Equation: m = h/ λc  M = mass in kg  h= planck’s constant (6.626 x 10^-34 in J.s)  λ in meters  C = in speed of light in m/s   De Brogile Equation: m = h/ λu  U = speed of the particle or a=object in m/s  When mass is large, wavelength is small (inverse)  Energy (E) is proportional to frequency: E = hν  Making Etotal = n or Na h ν  Where n is the number of quanta/ packets being transferred  1 photon = 1 quanta  Na is avogrado’s number  E photon = h (c/λ)

2. Explain Black Body Radiation in terms of what it measures and the relationship that can be seen between temperature and wavelength.

Group Practice: 1. Calculate the wavelength of each frequency of electromagnetic radiation: a. 100.2 MHz (typical frequency for FM radio broadcasting)    b. 1070 kHz (typical frequency for AM radio broadcasting) (assume four significant figures)    c. 835.6 MHz (common frequency used for cell phone communication)  2. Calculate the energy of a photon of electromagnetic radiation at each of the frequencies indicated in the question above A.    B.  

3 

C.  3. A heat lamp produces 32.8 watts of power at a wavelength of 6.5 um. How many photons are emitted per second? (1 watt = 1 J/s)  

Independent Practice: 1. How much energy is contained in 1 mol of each? a. X-ray photons with a wavelength of 0.135 nm    b. g-ray photons with a wavelength of 2.15 * 10-5 nm     2. The smallest atoms can themselves exhibit quantum-mechanical behavior. Calculate the de Broglie wavelength (in pm) of a hydrogen atom traveling 475 m/s.     3. A proton in a linear accelerator has a de Broglie wavelength of 122 pm. What is 4 

the speed of the proton?   

ACTIVITY Write down any questions you still have and post them to the discussion board on canvas to allow fellow students to answer them.

5 ...