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Archive – Q2  week 10 – 19-20

Week of 1/20 – 1/24
 
1/20 – Monday – 

 MLK

 

 
1/21 – Tuesday – period 2/3 – 
 

Light and The Photoelectric Effect

 

 
1. Ultraviolet Catastrophe explained- 
particle theory of the atom on a crash course with wave behavior of light
2: Light as wave – double slit – Thomas Young
               a) Laser pointer demo with double slit
 
                b) Destructive interference, Constructive interference     
 
                c) IR remote –        
 
3. photoelectric Effect – review – animation
 
4. Finish Hot air balloon construction.
      a) determine mass and volume
                                 period 4 – 
 
1.  PhotoElectric Effect – review
atomic structure – 1 – photoelectric effect KEY.pdf
View Download
period 4 whiteboard – particle theory and wave behavior going on the same time period and   
                                             collide with Niells Bohr!
 

 

1/21 – Monday Homework- 5 parts!
1. Make sure you have completed the Photoelectric Effect homework from the weekend.  The lectures/videos that are posted for these worksheets are posted under last Friday 1/17.
 
You already have these worksheet as you completed question 1,2,3 this week!
atomic structure – 1 – photoelectric effect.pdf
View Download
 
atomic structure – 1 – photoelectric effect KEY.pdf
View Download
 
 
2. HW:  Please Read Below:  ALSO I AM COLLECTING A HW SOMETHING FROM THIS WEEK!!!
 
Up to this point we have discussed how Plank gave us the concept of quanta – discreet energy requirements for the oscillators in a Black Body Radiator. And how Einstein gave us the concept of photons (light existing as a particles of energy) in his explanation of the photoelectric effect.  Einstein postulated that light is quantized and that matter (atoms) is quantized by the quanta of light it can accept.  His contribution was vital to the development of quantum mechanics in that electrons and photons are paired with one another in energy changes of matter.  Also the contribution that light can have particle (mass) properties and wave properties (particle/wave duality) was monumental for the development of quantum mechanics.
 
So Plank uncovered the secret to the Ultraviolet Catastrophe and Einstein the photoelectric effect.  Both were phenomenon that classical  physics could not explain.  
 
Bright Line Spectra was another phenomenon that know one knew how to explain and yet since the 1850’s it was used to identify elements based on the type of light emitted by elements when they are subject to high energy.
 
Here is a simple animation on how it is determined:
 
These Bright Lines, Photons of a specific Energy ( E = hv) are emitted from each element differently and thus can be used to identify elements.  Helium, He was discovered from the light given off from the sun.  Light from the sun was diffracted and all of the bright lines were identified from all known elements at the time and the Bright Lines that remained was thought to have come from a new element that was yet to be discovered on earth.  They called it Helium, the Greek God of the Sun (Helios). Thirty years later Helium was discovered on Earth and it had the same spectral lines as the mysterious new element discovered on the Sun!
 
I will perform this demo tomorrow and we will look at the spectral lines of a few elements and some molecules.
 
Neills Bohr was the first to explain this phenomenon by creating a model of the atom that suggested that the energy levels in an atom are quantized and that the spectral lines are due to electrons making quantum leaps from higher to lower energy levels. 
 

 

  Bohr took Plank’s and Einstein’s ideas as was the first to make a quantum model of the atom that stated that electrons can only have discreet energy levels (quanta) and that when they move (quantum leap) the energy changes result in photons of light being released (when moving back to the ground state) or absorbed (when moving to higher energy states).  Before Bohr the model of the atom was Rutherfords, where electrons orbited the nucleus but could have any energy
3: Please watch (I am being tall and polite) the lecture below and follow me through the backside of the  Atomic structure 2 – bohrs.pdf worksheet.
 
THE last question should read:
 
Calculate the Energy needed for an electron to transition from the 4th energy shell to the 2nd energy shell?  What color of light is this.
4 Complete questions 1 and 2 in atomic structure 3 worksheet and review with the key. 
     
Atomic structure 2 – bohrs.pdf
View Download
 
atomic structure 2 – Bohr Key p.pdf
View Download
 
atomic structure 3 – de Broglie Key.pdf
 
Atomic structure 3 – de Broglie.pdf
View Download
       
Lecture for the homework:

 

Notice the Balmer Equation: En (for hydrogen only!!)

 
5.  Complete the Form Below after or with the Photoelectric Effect Simulation lecture below .
Photoelectric Effect Lecture with simulation:
 

 

Tonights Form:

Photoelectric Effect

 

 

End of Tuesday!



1/22 – Wednesday – period 2 

 
1.  Beginning of Bohr model explained
 
2.  Ruben’s Tube Demonstration.
wave behavior demo:
 Sound waves, calculation of speed of sound – tied to type of molecules.
 beat frequency
 
 Period 2 Ruben’s tube performances:

 

                                period 2/3
 
1.  Beginning of Bohr model explained
 
2.  Ruben’s Tube Demonstration.
wave behavior demo:
 Sound waves, calculation of speed of sound – tied to type of molecules.
 beat frequency
 
 Period 3/4 Ruben’s tube performances:
 

 

 

Ruben’s Tube Demo explained  – Grodski
1/22 – Wednesday – Homework:
 
1.  Please make a second submission to last nights form.
 
2. Clash of Titans Timeline continues.  Please continue with your timeline from 27:00 – 34:55.
Sorry but this one will have Spanish subtitles..
 
or
https://www.youtube.com/watch?v=Y-AiqCp7Vlc
NO subtitles!!!
 

1/23 – Thursday – period 2/3 – 
 
I started today talking the bright line spectrum that Bohr interpreted from the Balmer equations.
He was able to show the the “bright lines” of Hydrogen were the photons of light emitted by electrons returning to their most stable state (closer to the nucleus or mom). 
 
These Bright lines were made by pure elements being “excited with energy” (electrons moving away from atom in higher energy shells) in gas discharge tubes and when these excited electrons move back to their stable low energy positions photons of light are emitted that are specific to electron moving or transitioning from a higher energy shell to a lower energy shell.
 
Bright line spectrums were know since 1850’s and were specific for each different element.  This means that each different element had its own unique spectrum could be used to identify elements. It was a spectral fingerprint.  The Bright line spectrum was used to discover Helium from light of the sun 30 years before it was discovered on Earth.
 
1. Standing waves  animation- Ruben’s Tube demo complete – measure speed of sound in propane.
                                                       Beat frequency!
 
2.  Review/Positive and Negative theories of light – color blindness test
 
3.  Positive theory – color wheel/ light stick wheel/ sunset demo / phosphorescence demo /
4: Neils Bohr model of the atom – light theories begins
                
Emission spectroscopy – Bright line spectrum – demo
 
absorption spectroscopy
 
Review:
atomic structure 2 – Bohr Key p.pdf
View Download
 
atomic structure 3 – de Broglie Key.pdf
 
                               period 4  – 
 
Opening thought on Bright Line spectrum- 
 
1. Ruben’s Tube Revisted – Beat frequency!
 
2.  Review/Positive and Negative theories of light – color blindness test
 
3.  Positive theory – color wheel/ light stick wheel/ sunset demo / phosphorescence demo /
 
 
4: Neils Bohr model of the atom – light theories begins
                
Emission spectroscopy – Bright line spectrum
 
absorption spectroscopy
   Sunset Demo:

1/23 – Thursday Homework:

 
1. Please complete the Bright Line spectrum worksheet.

Bright line spectra – .pdf
View Download
 

Bright Line spectrum Key p.pdf
View Download

Notice the Balmer Equation: En (for hydrogen only!!)

End of Thursday..


1/24 – Friday – period 2
 
1: Neils Bohr model of the atom – determination of the spectral lines of Hydrogen
    Flash animation – quantum leaps in hydrogen
 
Homework review:
Bright Line spectrum Key p.pdf
View Download
IR remote demo- 
Newton’s wheel – 
– Balmer equation is really Coulombs Law —> Inverse square law!
– Light dissipation also follows an inverse square law.
   inverse square law light dissipation demo
– phosphorescence demo: Quantized energy levels
 
3: limitations to Bohr’ s model
 
4:  absorption spectroscopy – did not get to – Monday!
                                – period 3/4
1: Neils Bohr model of the atom – determination of the spectral lines of Hydrogen
   Flash animation – quantum leaps in hydrogen
                
2: Emission spectroscopy – Bright line spectrum – demo
3:  absorption spectroscopy – demo
    Newton’s wheel – 
– Balmer equation is really Coulombs Law —> Inverse square law!
– Light dissipation also follows an inverse square law.
   inverse square law light dissipation demo
– phosphorescence demo: Quantized energy levels
4: limitations to Bohr’ s model
 

Newton’s wheel demo (last year):

                                    
Bright Line Spectrum Playlist – 
                   
phosphorescence demo:
Absorption spectroscopy demo (period 2 class will do this Monday): 
 
1/24 – Friday – Homework – 
 
1.  Clash of Titans Timeline continues.  Please continue with your timeline from 33:00 – 1:00:00
Please complete the timeline of all accomplishments big and small of all players that contributed to atomic theory.
Clash of the Titans
https://www.youtube.com/watch?v=Y-AiqCp7Vlc
NO subtitles!!!
 
 
2.  Please view the lecture that will be posted this weekend.
 

 

3. Please complete the de Broglie worksheet and review with the key. 
     You should only have questions 3 and 4 left!
 
For those that did not have me discuss Louie De Broglie please still complete questions 3 and 4 using the following formula:
 

 

This was a formula that from a PhD student that needed Einsteins approval.  It used Einstein’s formulas to form a new formula that proposed all things that have matter also have wavelengths! Or better yet, all things that have matter also have wave behavior!  This was the first proposed idea of wave /matter duality that was needed for Quantum Mechanics.  Einstein loved the work because it allowed the conservatives to view the atom exclusive of the mathematics of the Copenhagen interpretation of quantum mechanics (Niel’s Bohr’s group).
atomic structure 3 – de Broglie Key.pdf
 
Atomic structure 3 – de Broglie.pdf
View Download
4. Please complete form below: 
 
*Please use 1 m/sec for the velocity of the proton in question 8 of the form.

Bohr to DeBroglie Atomic Structure Form

End of week 10 and the second quarter!