AP Chem – Q3 – week 1 – 21-22 | Mr. Grodski Chemistry

Q3: Week 1 – 1/31 – 2/4

Jump to: Tuesday, Wednesday, Thursday, Friday ^{______________________________________________________________}

1/31 – Monday – A Day – 2/3a Lab, 4

Main focus –

a) To Complete the Gas Law Test.

b) To Begin our discussion of atomic structure

Period 2/3: –

1. Complete the Gas Law Test.

2. Atomic Structure Begins!

Period 4: –

1. Complete the Gas Law Test.

2. Atomic Structure Begins!

Connections:

We have for the last 5 months have been on tour through many topics of chemistry (redox, solution, acid/base, etc.) using the mole concept to perform stoichiometry. Stoichiometry requires a particle and mole concept to predict and calculate the values of our chemical reactions and of course to determine the chemical formulas of our chemicals themselves. We have been using the macro approach to chemistry as we have been looking at groups (moles) of molecules and formulas (if salts) to using the ratios to answer so many chemical questions. We have not considered the micro approach yet AND NOW we will. We will now look at the structure of atoms.

Before we begin with Atomic Structure we need a segway! The first day must connect to the last day! The connection is very easy. Historically we studied the development of the particle (atom) theory with the mole theory. Both of these ideas were necessary in order to do any stoichiometry. REMEMBER that chemistry really only began in the Karlsruhe Congress in 1860 when Stanislao Cannizzaro championed Amedeo Avogadro’s notion that equal volumes of gas at the same pressure and temperature held equal numbers of molecules or atoms, and the notion that equal volumes of gas could be used to calculate atomic weights.

Chemistry began when we USED GASES that we cannot see to determine what the atoms or their arrangements looked like from Gay- Lussac’ s whole number volumes when he reacted gases with gases.

Using Avogadro’s hypothesis ( V = n * K) Cannizzaro was able to for the first time show that stoichiometry can be done for chemical reactions as the molecular formulas of chemicals could be determined!!! He essentially was able to fill the boxes with what the arrangements of atoms MUST be IF YOU ACCEPT 2 NOTIONS:

1. ATOMS are neither created nor destroyed BUT just rearranged (LAW of Conservation of Mass)

2. Equal volumes of 2 (IDEAL GASES) MUST have the same number of molecules if they are

under the same Temperature and Pressure (Avogadro’s Hypothesis!)

WE USED GASES TO DETERMINE ATOMS!

So it only makes sense that we now look more deeply at the particles we discovered through our understanding of gases!

So we begin Atomic structure.

Atomic Structure 1 Presentation (end of the particle theory presentation):

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1/31 – Monday Homework: –

1. If you have any late work that needs to be handed in, now is the time to get to that to me ASAP.

Please write an email letting me know what you made up or a shared link of the work.

2. If you are all caught up then you can chill or go outside and freeze.

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2/1 – Tuesday – B Day – 2, 3b/4 Lab

Main focus –

a) To Review the experiments of JJ Thompson, R. Miliken, Earnest Rutherford

b) To Review the experiments of H.Moseley and Chadwick

Period 2:

1. Complete J.J. THompson’s cathode ray experiment, Miliken’s Oil drop, Rutherfords metal foil explanations.

2. H. Moseley, Chadwick

Period 3/4:

1. Atomic Structure Begins – “connections”

2. Complete J.J. THompson’s cathode ray experiment, Miliken’s Oil drop, Rutherfords metal foil explanations.

3. H. Moseley, Chadwick

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Cathode Ray Tubes NOTES :

Thomson presented three hypotheses about cathode rays based on his 1897 experiments:

Cathode rays are charged particles (which he called “corpuscles”).
These corpuscles are constituents of the atom.
These corpuscles are the only constituents of the atom. The third hypothesis was proven false by his student Earnest Rutherford ( the father of the atomic structure).

As a result of J.J Thompson’s experiments he developed a model of the atom, where electrons existed as very small negatively charges particles in a massless positive cloud. This was called the “Plum Pudding” or “Raison Cake” model.

electricalfundablog.com/

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2/1 – Tuesday Homework: –

1. The Mass Spectrometer Assignment – Detecting Isotopes and determining average isotopic mass.

A) Please listen to the video on the basics of mass spectrometry below:

B: Please follow along with me with worksheet and video below:

Atomic Structure Isotopes Mass Spectrometer.pdf
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Atomic Structure Isotopes Mass Spectrometer Key.pdf
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C: Please read about the mass spectrometer using the link below:

http://www.chemguide.co.uk/analysis/masspec/howitworks.html

D: Complete the Atomic Structure – Mass Spectroscopy .pdf worksheet and review with the key.

Atomic Structure – Mass Spectroscopy .pdf
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Atomic Structure – Mass Spectroscopy Key.pdf
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F: Complete the form: Mass Spectrometer – Isotope Determination – 21-22

******Question 5 will reveal itself after or during Questions 6.

You will have a total of 1 submission to this form:

1: Mass Spectrometer- Isotope Determoination Form::

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End of Tuesday!

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2/2 – Wednesday – A Day – 2/3a Lab, 4

Main focus –

a) To complete atomic structure experiments that lead to the Mass Spectrometer

Period 2/3:

1. Complete the Atomic Experiments from Earnest Rutherford —-> Moseley —–> Chadwick

2. Mass Spectrometer Review –

a) Isotopes, weighted average problem, atomic mass, most abundant naturally occurring isotope.

3. Particle Theory on Direct Course to collide with or Light or wave theory!

particle theory of the atom on a crash course with wave behavior of light

Light as wave – double slit – Thomas Young

a) Laser pointer demo with double slit

b) Destructive interference, Constructive interference

c) IR remote –

4. Ultraviolet Catastrophe!

Light and The Photoelectric Effect

Period 4:

Same as above –> Moseley —> Chadwick —> Mass Spectrometer

Atomic Structure 1 Presentation (end of the particle theory presentation):

Light into the Bohr Model:

1: Ultravioloet Catastrophe Form::

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End of Wednesday!

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2/2 – Wednesday Homework: –

Tonight we will investigating another phenomena that could not be explained (like the Crook’s Tube) that wound up starting the Quantum revolution in physics! At the time (1895 ) it was thought there was nothing more to discover in physics and BUT there was a REVOLUTION coming that will pit classical old world physical ideas against a NEW form that will challenge and rock the scientific community to its core.

The particle theory of the atom (electrons) WAS ON A a crash course with the wave behavior of light.

It all begins with explanation of the ultraviolet catastrophe that began this Revolution.

1. Please view the lecture (Lecture 2.11) from 0:00 – 8:01 and complete ONLY question 1 with me on the worksheet.

atomic structure – 1 – photoelectric effect.pdf
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atomic structure – 1 – photoelectric effect KEY.pdf
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Grodski Lecture: (part of lecture) 0:00 – 8:01

2. Please view the Plank’s Constant and the Origin of Quantum from 2:56 – 15:15.

PBS Digital Studios (part of video) watch only 2:56 – 15:15

3. Please complete the Form below on the Ultraviolet catastrophe – You will be directed us the other resources below for a particular question in the form.

Figure 1:

Grodski Wave Demo:

Article for question 10:

https://drive.google.com/file/d/1gnuNlXM6rE7iffCe2n_UBLFyLFtywcZx/view?usp=sharing

From our reference tables:

NOTES On the Ultraviolet Catastrophe:

There is just not enough energy present at fixed temperatures to elicit high frequency radiation because the oscillators (electrons and atomic nuclei) are taking in the energy in constant chunks (photons) and re-emitting these photons. The energy is not a constant flow and does not build up.

The heater in the Black Body radiator makes the atoms vibrates at all different frequencies and thus a wide range of photons are released because temperature is proportional to molecular motion range.

The lower energy vibrations use up the energy first, leaving very few chunks or quanta to excite the higher energy vibrations. The higher energy vibrations (at the smallest wavelengths) are needed to elicit higher frequency radiation and there is just not enough of these photons available.

With classical physics, energy is a continuous stream of energy, and oscillators in the black bodies can vibrate with ANY frequency thus have an infinite amount possible frequencies or modes. Classical physics suggests that kinetic energy that is absorbed is absorbed evenly throughout every possible mode (or frequency ). This is called the Equal Partition Theorem and this theory work very well in many cases to predict kinetic energy in many systems. It did NOT do very well in the explanation of wavelengths emitted from black bodies. Its formulas (of equal partition called the Rayleigh Law) led us with predictions that led to the “catastrophe” because energy that was absorbed by the black body was absorbed equally by all modes of vibration. Because there are more vibrational modes that are smaller (limit to zero) these high frequency modes would gain more of the energy than the less frequent lower frequency modes.

Max Plank’s new formula was able to predict the experimental results IF the frequency which is proportional to the Energy ONLY existed in discreet bundles and was not continuous! That is matter in the black bodies could not vibrate at any frequency and absorb ANY amount of energy. They could only absorb certain energy amounts AND only start vibrating or oscillating at certain frequencies!

Max Plank started the quantum revolution!

E (energy) = h * f

Energy = Planks * frequency

Constant

Planks Constant represents a proportionality constant (price per seat!) or the smallest divisible value that frequency (can have).

It represents the “energy chunk” = 6.63 x 10^-34 J s (Joule seconds)

Energy is absorbed in chunks of this small value x the frequency of the oscillator.

Energy is not continuous!!!!

The oscillator of course are the atoms!!!

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2/3 – Thursday – B Day – 2, 3b/4 Lab

Main focus –

a) To discuss the Ultraviolet Catastrophe as the beginning of Quantum Theory

b) To Begin the Photoelectric Effect

Period 2: –

1. Ultraviolet Catastrophe explained-

– particle theory of the atom on a crash course with wave behavior of light

2: Classwork problems with wave equations

Atomic structure 2 – bohrs.pdf
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atomic structure 2 – Bohr Key p.pdf
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3. photoelectric Effect – review – animation

Photoelectric Effect Lecture with simulation:

Period 3/4: –

Same as above.

Phet demo – Blackbody radiation

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Lecture 2.11C – Electromagnetic Calculations (side 1 0f atomic Structure 2 – Bohrs):

Photoelectric effect – Phet demo

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2/3 – Thursday Homework: –

1. Complete the photoelectric effect worksheet (side 1 and 2) and review with the key or use the videos posted below to review. You should of completed the first question from side one last night. If you need a review of the concept of the photoelectric effect, there is a lecture posted below (last one for today) for your viewing pleasure.

atomic structure – 1 – photoelectric effect.pdf
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atomic structure – 1 – photoelectric effect KEY.pdf
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Lecture that reviews first side of atomic structure – 1 – photoelectric effect worksheet.

Lecture that reviews the second side (questions 5 and 6):

2. Complete questions 1,2,3 on the following worksheet and review with the key or the video below:

Atomic structure 2 – bohrs.pdf
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atomic structure 2 – Bohr Key p.pdf
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Lecture on atomic structure 2 – Bohrs worksheet – (front side):

Photoelectric effect Explained – Phet demo

EMax _________________________________________________________________________________________________________________________

2/5 – Friday – A Day – 2/3a Lab, 4

Main focus –

a) To Review how Max Planck solved the Ultraviolet Catastrophe.

b) To Review how Albert Einstein interpreted the Max Planks equation and used it to explain the Photoelectric Effect.

c) To solve wave problems using the light equations equations by Maxwell, Plank and Einstein.

Period 2/3: –

1. Connect the Max Planks Ultraviolet Catastrophe to Einsteins Photoelectric effect.

2. Use the PHet simulation to teach the Photoelectric effect = E becomes the E (p)!

a) redox implications Na vs, Cu!

3. Review the light equation and Photoelectric homework

4. Light theories (Maybe)

Period 4: –

1. Quick Review of the photoelectric effect

2. Review the light equation homework

3. Light theories (Maybe)

TODAY’s NOTES:

1. Plank and Einstein’s contribution to the development of the duality of particle and wave behavior of light.

Plank = Energy was quantized by a multiple of (h) = Plank’s constant

Einstein = Light was quantized into packets called photons and each electron interacted with a single photon

a) Review of the photoelectric effect with animation.

These ideas was on a crash course towards the particle model of the atom

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.

Light into the Bohr Model:

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2/5 – Weekend Homework: –

1. Timeline Activity

2. Photoelectric Effect Form

Clash of the Titans: Clash of the TITANS – movie note taking – (instructions below)

Timeline activity – from 00:00 – 27:35 only this weekend!

Please make a timeline of important events that lead to the

development of quantum mechanics (our current model of the atom).

Time line activity – Trace the important moments in the development of the atom.

Scientists – dates – places – accomplishments – anecdotes –

This will be collected once it is completed and YOU ARE ONLY STARTING it!

I am asking that you start your timeline from 00:00 to 27:35 of the Clash of the TITANS movie below.

Clash of the Titans

http://topdocumentaryfilms.com/atom-tim/ or https://www.youtube.com/watch?v=Y-AiqCp7Vlc

I will be collecting this once we complete the entire timeline next week!

I have an example posted below which you should model the rest of your Timeline from.

My Example:

Photoelectric effect Explained – Phet demo

2 : Photoelectric Effect 21-22 Form: This form will be Monday’s Homework BUT…

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End of Wednesday!