homepage    mcep   e-portfolio                  <-- PREVIOUS REFLECTION                NEXT REFLECTION -->
  Home            MCEP home     E-portfolio


Reflection 5: Use of New Content Knowledge in Designing Instruction

How the rubric item was addressed in this reflection:

This reflection shows how I have applied new scientific knowledge in the design of teaching materials, lesson plans, and/ or assessments used in my own classroom.

WHAT is the evidence? WHY did I choose the evidence? HOW does the evidence show growth?

Through my participation in the MCE courses, I have learned content in a way that has made me want to make my lessons more conceptually sound and more easily connected to real-life phenomena. 

I present 2 sets of evidence (baseline and later) consisting of previous and new teaching materials.  The first piece of later evidence shows how I have progressively increased my integration of Coulomb's Law (after one groundbreaking POGIl from Chem501) into my lessons, particularly in my intermolecular force unit.  The second piece of later evidence shows a lesson on (additive or light) color perception (as opposed to subtractive or pigment color perception) and fluorescence (from Chem507) that I plan to use in conjunction with my quantum theory unit this coming year (2009-2010).


EVIDENCE #1:
Integrating an Understanding of Coulomb's Law
Into the Intermolecular Force UNIT
THE CONTENT
Dr. Robert's Coulomb's Law POGIL (from Chem501): (click for larger view)

ef pogil

Through my coursework in Chem501, Chem503, and the integration of the concept of Coulomb's law (shown in the above POGIL), I have gotten a deeper appreciation for how integral and understanding of this law is to chemical phenomena.

COULOMB'S LAW states the relationship between potential energy or electrostatic force (of attraction or repulsion, depending upon the sign of the charged particles involved) and charge magnitude and distance.  As charge magnitude increases, the magnitude of the electrostatic force increases; as the distance increase, the magnitude of the electrostatic force decreases.

Coulomb's law has been mentioned and can be applied to various chemical concepts.  For example, the concept of shielding electrons can be explained by the competing electrostatic forces acting upon a valence electron.  Furthermore, Coulomb's law is also integral to an understanding of intermolecular forces and how polarity and the ability of molecules to pack closely together impacts properties such as tensile strength, boiling point, and viscosity.

Baseline evidence:
  1. Old worksheets on intermolecular forces (IMFs)
    JANUARY 2007
 Later evidence:

  1. Excerpts from content-integration project report in Chem503
    JANUARY 2008
  2. Reading assignment used in conjunction with intermolecular forces lecture and lab
    JANUARY 2009
  3. Coulomb's Law and Intermolecular Forces POGIL
    (made for future use)

I had NOT taught Coulomb's Law as the basis for intermolecular attractions or periodic properties related to shielding before taking Chem507.

Old worksheets on intermolecular forces
(click on image to see larger view of highlighted view)
imfold


From content-integration project in Chem503:
(click on image to see larger view of highlighted view)
content integration

Intermolecular Force Reading Assignment
p. 2, Questions #6-12
(click here for full .pdf)
(click on image to see larger view of selection section)
imfpogil

Coulomb's Law POGIL & HW
(click on image for full .pdf)
coulomb pogil

Intermolecular Forces POGIL
(click on image for full .pdf)
imf pogil
REFLECTION ON GROWTH
Comparison of the baseline and later evidence shows a shift from having students learn only what an intermolecular force is and the properties it is related with toward having students also connect this understanding to Coulomb's law of electrostatic attraction (a law of physics).  I would not have integrated these concepts and pushed my students toward a deeper understanding (one based on physical laws) had I not encountered Dr. Robert's Coulomb's Law POGIL in Chem501.  Future growth (in the coming years) will consist of trying to integrate this law into other units where it applies (e.g. shielding in the periodic properties unit).



EVIDENCE #2:
Integrating Lessons on Color Perception and Fluorescence
Into the Quantum Theory UNIT
THE CONTENT
My molecular spectroscopy project on fluorescent brightening agents (from Chem507):

Through my regular coursework and my molecular spectroscopy project on fluorescent brightening agents (FBAs) in Chem507, I have a newly acquired understanding of color perception, fluorescence, and its applicability to real life (e.g. lightbulbs, paper dyes, laundry detergent additives).  I wanted to integrate these interesting concepts into my quantum theory unit to make the concepts more tangible and relevant to my students..

Color Perception
color wheeladditive mixing reflection    White light can be broken down into a range of wavelengths with characteristic colors shown in the first image--the color wheel.  When various colored lights are emitted simultaneously or overlap, the human eye cannot differentiate between the disparate wavelength lights, but rather perceives a different hue which is a mix of the two (e.g. instead of seeing both red and green simultaneously, a person would see the color yellow).  This "additive" mixing is shown by the second image.  The perception of color as a property of an object occurs when that object absorbs certain wavelengths and reflects others.  The third diagram shows an example of this absorption and reflection that makes an object appear colored.  In this example, the object would appear yellow because it would absorb blue light, but reflect red and green light.  In the simplest case, when a particular wavelength light is strongly absorbed, its complementary color (located on the opposite side of the color wheel) is observed.  

Fluorescence
fluoresWhen substances fluoresce,

1. An electron is excited from the ground electronic energy state to an excited electronic energy state by the absorption of energy, typically ultraviolet light.  During this transition, the vibrational state also changes according to the Frank-Condon principle (which states that the internuclear distance cannot change).

2. The electron relaxes to a lower vibrational energy level in the excited state via a radiationless transfer (i.e. collision) or by the release of an infrared photon.  This transition is fast.

3. The electron relaxes from the excited state to the ground state, emitting a photon.  This transition is slow and typically in the visible range, yielding fluorescence.

(A similar mechanism occurs for phosphorescence, but the second step is slower as a result of a forbidden transition, allowing for a prolonged lag between initial excitation and visible light emission)

Fluorescent Brightening Agents (FBAs)
ooh moo mehFBAs are essentially fluorescent dyes that act similarly to the quinine in tonic water, which emits blue light under blacklight.  FBAs contribute to the perception of brighter and whiter whites and colors by absorbing UV light and emitting blue light.  This disguises the natural yellowing that often occurs as white linens and clothes yellow with age and contributes to a brighter product.

Baseline evidence:

OLD LESSON PLAN:
(Electromagnetic radiation and quantum theory)
2008-2009 school year
 Later evidence:

NEW LESSON PLAN:
(Color vision and fluorescence)
planned for 2009-2010 school year
JANUARY 2010

I had NOT taught color perception or fluorescence in concert with my electromagnetic radiation and quantum theory before taking Chem507.

Day 1-2: Electromagnetic radiation/ intro to quantum theory with atomic emission spectra lesson

Note sheet
(click on image for full .pdf)
em notes

Powerpoint to go with lesson
Light


-Atomic emission spectra applet
-Students use spectroscopes to view various light sources (mini-lab activity); results are discussed in class; reviewed with notes

Day 3: Bohr model lesson
-Bohr model applet and website with wavelengths of emission, students asked to do calculations of energy transitions corresponding to visible light
Applet
(click to link to applet site)
bohr

Day 4: Flame test lab
-student observe characteristic colors of chloride salts of Li, Sr, Ba, K, Na, and Cu, and although the colors observed are a composite of various emitted wavelengths, students choose a main "representative" wavelength for the color seen and calculate the frequency and energy associated with the emission of that color light
Flame test lab
(click on image for full .pdf)
flame test lab

Day 5: QUIZ

Day 6-7: Electron configurations/ atomic orbital diagram lessons
-lecture/ several worksheets (some representative worksheets shown)

E- configuration worksheet 1
(click on image for full .pdf)
sample1

E- configuration Worksheet 2
(click on image for full .pdf)
sample2

Day 8-10:
-QUIZ
-Review
-TEST

Click here for the full original lesson plan from the molecular spectroscopy project.

Previous Days:
-electromagnetic radiation lesson
-intro to quantum theory with atomic emission spectra lesson

Day 1:
POGIL PhET applet activity on color vision
(click on image for full .pdf)
colapp

The color applet activity that describes how various wavelength (i.e. color) lights produce a particular perception of color (e.g. a combination of green and red light creates the perception of yellow colored light) would help students understand how the different bands of light in an element's emission spectrum produce the perception of a particular color (e.g. the pinkish glow of an argon spectral tube even though its emission spectrum shows blue, green, and red bands).  Furthermore, I thought it would be an interesting foundation concept to learn, especially for students interested in stage lighting and photography.

Day 2:
-discussion/ review of POGIL PhET applet activity
-small QUIZ on electromagnetic radiation/ color perception
-(some lecture/ old lessons on quantum theory)

Day 3-6:
-continue old lessons on quantum theory (electron configurations, atomic orbital diagrams)
-do flame test lab
-small QUIZ on quantum theory
-some lecture on fluorescence

Day 7:
Fluorescence worksheet
(click on image for full .pdf)
fluor wkst

Day 8-9:
Fluorescent brightening agents in laundry detergent LAB
(click on image for full .pdf)
lab

Day 10: TEST

Beyond the use of fluorescent light bulbs, most students are unaware of how pervasive fluorescence-based applications are.  The ability to absorb higher energy, invisible UV light and emit lower energy visible light has allowed for the creation of "brighter" pigments and colors that can also appear "whiter" if the proper wavelength light is emitted (going back to the first, color perception lesson).  I thought this lesson would connect quantum theory with something more tangible in the everyday routine of an average student.