Amy Hruska
Video Analysis – April 26, 2011
Prior to viewing the lesson:
Tabb High School utilizes a spiral curriculum where the same eight topics are taught each unit
but as the year progresses the students build on those eight topics each unit. The lesson taught on April
26th was the final aspect of chemical reactions that students had yet to learn. In unit 2 students learned
how to name and write ionic compounds, in unit 3 students learned how to name and write covalent
compounds, in unit 4 students learned how to balance chemical reactions, in unit 5 students learned the
difference between synthesis and decomposition reactions, in unit 6 students learned the five general
types of reactions and how to predict the products, in unit 7 students learned about neutralization
reactions, and finally in unit 8 students will learn about oxidation/reduction reactions and how to
balance chemical reactions based on the flow of electrons.
In the lesson prior to this lesson, I taught the students about equilibrium and Le Chatelier’s
principle. Building on the concept of equilibrium and all of the previously covered material on
chemical reactions, I fostered student exploration of oxidation/reduction reactions through the
Belousov-Zhabotinsky Oscillating Reaction, a demonstration where a continuous rotation between four
colors is observed for about 35 minutes within a single beaker. I created a demonstration handout that
had questions to activate students’ prior knowledge and promote observational analysis of the reaction.
By incorporating a handout with my demonstration, I hoped to foster participation from the entirety of
the class because I think that by just having a class discussion some students are never asked to
formulate their ideas into their own words making the material their own. A goal for the demonstration
was to get students thinking about the flow of electrons and have students formulate into words new
scientific concepts.
I then planned to transition from the demonstration to the specific notes on the topic by placing
chemical equations on the board and prompting the students through identifying the charges so that
they could determine which atoms had a change in charge throughout the chemical reaction. I
distributed a notes sheet so that as we were going through the reaction analysis the students could
reference the notes. I modeled identifying the charges, more formally known as oxidation numbers,
and how to write half-reactions. I also told the students two different mnemonics to help them
remember the difference between oxidation and reduction. During this section, my goal was to have
students grasp the entirety of the basics of chemical reactions and understand how everything they
have learned throughout the year on this topic is intertwined. I also wanted students to be able to relate
this concept to real life applications so that the students understand the chemistry behind an oxidizing
agent or why and how things like the Statue of Liberty have changed colors.
I chose to have the students simulate the reaction that occurred on the Statue of Liberty for the
formation of the patina through a mini oxidation/reduction reaction two-day lab. At the end of today’s
lesson, students were expected to set-up three different solutions, make observations and then allow the
solutions to react over night for more observations and analysis to be made at the beginning of the next
class period. The goal of this reaction was to give students a hands-on experience with redox reactions
and then take their observations and apply and relate them to answering the question: why is the Statue
of Liberty green if it is made out of copper?
Overview of Lesson
Activity
Check Homework &
Answer Questions
Concept
Explored/Reinforced
Rates of Reaction
Goals
To observe student
misconceptions
Time
Allotted
10
Quiz – Collgiative
Properties & Le
Chatelier’s Principle
Colligative Properties &
Le Chatelier’s Principle
Belousov-Zhabotinsky
Oscillating Reaction
Demonstration
Electron flow throughout
a reaction
Redox Notes with
Modeled Examples &
Embedded Practice &
Copper Sulfate with
Iron reaction
Statue of Liberty –
Redox Lab (2 day lab)
Oxidation numbers,
writing half reactions,
identifying which specie
is being oxidized and
which is being reduced
Identifying compounds
oxidized and reduced
through application of
redox reactions
16 multiple choice questions
that will give formative
feedback to students on their
comprehension of the material
To have students realize
through inquiry based
questioning that reactions
occur due to the transfer of
electrons and that the shifting
of electrons must be balanced
To have students understand
oxidation and reduction and
how it relates to chemical
reactions.
To have students observe the
effects of acid rain and salt on
metals and how the observed
reaction impacted the coloring
of the Statue of Liberty
25
15
15
20
I taught this lesson four times and taped my first run through. I had intended to tape my last run
through as well but forgot to hit the play button though everything was set-up. Note that my first run
through was by far my worst delivery of a lesson during my student teaching. The flow of the lesson
was illogical and jumpy, I let the students control the pace of the lesson so we didn’t get to all of my
planned activities or meet all of my goals, and finally I lost my temper twice. Reflecting on the lesson,
before viewing the video, I decided to change my presentation of the content but kept the activities the
same. When I taught this modified lesson three more times, it was more effective in reaching my goals.
I do wish that I had taped my modified lesson so I could see my changes in action.
After viewing the video:
About 15 minutes into the lesson I can hear one of my students on the tape whisper, “Let’s
pretend we don’t understand this stuff, so we don’t have to do the lab.” There plan worked, I let the
students run the pace of the lesson because I desperately wanted them to understand the material even
though the majority of the class was ambivalent and unmotivated towards comprehending the material.
Though I didn’t hear the student say those words during the lesson, I could sense that the class was
trying to slow down the pace of the lesson because the class as a whole despises doing any type of
work. I find this classroom dynamic so perplexing, because my other three classes are always enthused
by the activities I create and the majority of the students engage with the material without prompting.
What do you do when an entire class is unmotivated and feed off of each other’s negative energy?
Putting the students behavior aside, the lesson overall was not delivered in the most effective
way. I had one hour to present my oxidation/reduction lesson, since the students spent the first thirty
minutes of class taking a quiz and showing me their homework from the night before. Since students
finish assessments at different paces, I like to have questions for them to answer while they wait that
will get them thinking about the lesson to come. Designing lessons in this fashion helps to reach my
goal of having students discover the material on their own being able to articulate the material so they
can take ownership of the material. Watching the video solidified what I already had discovered, that
the questions I had posed to the students did not set them up for success with the material or activate
the appropriate prior knowledge to get them thinking about the material to come. When I taught the
lesson again, I changed the questions so that they built logically from prior knowledge and provided a
stepping-stone for which we could build on with the demonstration.
During the demonstration, first I was not safety conscious and began pouring chemicals without
goggles or gloves but quickly corrected myself. Second, the students were more concerned with filling
out the demonstration handout then actually watching the really awesome demonstration. Third, during
my questioning I should have asked students direct focused questions pertaining to mixing,
equilibrium, reaction rates… instead of general ‘what are your thoughts’ type of questions. Fourth, and
finally, I should have related the demonstration to things like the iron levels in blood (when pouring in
the final solution and students were denoting the color) and this particular reactions relevance to lava
lamps. Making these small adjustments would have significantly improved the ease at which students
achieved my goals for this activity.
I did a much better job with my demonstration embedded within the lecture portion of the
lesson because the students could visually see that the iron was being oxidized and the copper was
being reduced and then we analyzed the correlating chemical equation. Though the demonstration
facilitated reinforcement of the content, I think that initially giving students a handout with the written
notes debilitated student comprehension of the details of this topic because from my observations
students do not read material that is given to them. This is one aspect of my lesson that I did not
change when I taught the lesson again due to the limited amount of time I had to cover this very
abstract concept. In the video, I saw myself continually answering the same question regarding
oxidation numbers for single atoms and diatomics reinforcing my observation that students do not read
notes given to them. If I had had the instructional time, I would have liked to have had students take
their own notes on the topic.
Finally, since the students had initially decided that they did not want to do the lab, I was
unable to fulfill my final goal of having students analyze and apply the concept of oxidation/reduction
reactions by simulating the creation of the patina on the Statue of Liberty. I am very disappointed that I
allowed the students to slow the pace of the lesson, because it is such an interesting and authentic
experiment. I wish I had some positive comments in regards to this first run through of the lesson, but
sadly I don’t. However, I do know that I continually improved as I taught the lesson to my other
classes. This lesson was assessed through a test on May 2nd, and I tallied the percentage of students
who correctly answered the redox questions. For my first time teaching the lesson, 76% of the students
answered the redox questions correctly. Once I tweaked the material 84% of the students answered the
redox questions correctly. From this data, I can conclude that all my students learned the material but
my students who had my modified lesson had the opportunity to make the material their own relating it
to real life examples that helped to solidify their comprehension.
Note: At the end of my DVD is a three-minute video clip of two of my students performing an
oxidation/reduction reaction. These two students found the experiment themselves and asked if they
could perform it after school. We did this experiment on the same day I had the camera, so I thought
you would enjoy seeing it! Also, I did not start recording until after quiz was over because watching
students take a quiz is not the most exciting thing to observe.