Backward Design Example

To begin thinking about lesson planning, I’ve chosen a standard from the Next Generation Science Standards that could be applied in a physics or chemistry classroom. Nuclear reactions are at the core of both atomic physics and nuclear chemistry so I believe this standard is important for use in both high school physics and chemistry. The lesson plan that I have devised is for a non-AP level course in either physics or chemistry. At the AP level students would be required to balance nuclear equations, but that is beyond the scope of the standard I have chosen.

The standard is as follows: Develop models to illustrate the changes in the composition of the nucleus of the atom and the energy released during the processes of fission, fusion, and radioactive decay. [Clarification Statement: Emphasis is on simple qualitative models, such as pictures or diagrams, and on the scale of energy released in nuclear processes relative to other kinds of transformations.] [Assessment Boundary: Assessment does not include quantitative calculation of energy released. Assessment is limited to alpha, beta, and gamma radioactive decays.] (HS-PS1-8)

The standard wants students to be able to illustrate various nuclear reactions qualitatively and to understand how to model changes during these reactions.

The big idea of this standard is that mass and energy interchange during nuclear reactions, but conservation of mass and energy still applies. This is specifically seen in understanding that in nuclear reactions atoms are not conserved, but the total number of protons plus neutrons is conserved.

To identify my learning plan for this unit, I first identified a number of proficiencies I wanted my students to achieve during the unit:

1.     Students illustrate that the total number of neutrons and protons are conserved in nuclear reactions.

2.     Students describe how the total amount of energy and matter in a system is conserved.

3.     Students illustrate the flow of matter and energy in and out of a nuclear reaction

4.     Students identify alpha, beta and gamma decays

5.     Students discuss different nuclear reactions in an informed manner with their peers and the teacher.

6.    Students can visualize different isotopes and show different numbers of neutrons in their visualizations.

To further identify what I want my students to be able to achieve during this unit I devised the following assessments:

1.     Final assessment where students are able to perform proficiently on written assessment that asks:

a.     Free response questions about alpha, beta and gamma decays

b.     Asks them to illustrate fission and fusion reactions

c.      Gives several multiple choice questions about the nature of matter and energy in nuclear reactions

2.     Final student presentation

a.     A short ~5 minute presentation to the class where they describe a nuclear reaction of choice.

b.     Show proficiency in illustrating nuclear reactions

c.      Show proficiency while discussing nuclear reactions

d.     Identify what type of decay is happening in their reaction

3.     Formative assessment using several quizzes are given throughout the unit:

a.     Quiz on the differences between fission, fusion and other decay processes

b.     Quiz on identifying nuclear reaction species: alpha, beta, gamma

c.      Quiz on neutron and proton roles in nuclear reaction and the conservation of mass and energy

4.     Research project on a nuclear processes

a.     Students identify a nuclear reaction that interests them

b.     Students write a 1-2 page report on the history/discovery of the reaction and its applications in the “real” world

To guide my students toward success in these assessments and proficiencies, I constructed a few learning activities that would help solidify the nuclear reaction concepts for my students:

1.     Group activity to understand alpha, beta and gamma decays

a.     Given in a group-quiz style

b.     Groups are asked to identify if the decay products are alpha, beta or gamma decays. No balancing of the equations will be needed.

2.     Workshop to learn how to illustrate fission vs. fusion

a.     Students work in groups and then independently

b.     In the style of “I do, we do, you do together, you do”

c.      By the end of the exercise, students are comfortable with the differences between fission and fusion

3.     Whiteboard session on fission, fusion and other decay processes

a.     Groups of students are given a fusion, fission or basic nuclear decay reaction on a note cards

b.     Students illustrate on a white board each of their reactions and then present to the class. Each groups is given a different reaction.

c.      When sharing the whiteboards to the entire class, the students are asked to identify familiar and different aspects of their reaction illustrations.

Finally, after specifying learning proficiencies, designing assessments and constructing activities, I have a good idea of how I want to structure my unit. I realize there are several lessons on foundational material that will have to occur first. This includes having students understand what an isotope is and what conservation of mass and energy really looks like. I also believe in putting science into an understandable historical context, so I will have an entire lesson addressing nuclear chemistry and its context in the making of the atomic bomb.

The learning units I propose after initial study are:

1.     Isotopes

2.     Conservation of mass and energy

3.     Fission vs. Fusion

4.     Alpha and Beta particles

5.     Gamma radiation

6.     Nuclear reactions and equations

7.     Historical context of nuclear chemistry: The Atom Bomb

I’m sure this unit will continue to evolve, but the analysis of proficiencies, assessments and learning activities gives me a good foundation.