In this lesson students continue to explore the NGSS Performance Expectation HS-PS1-8: 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. This lesson is a summary of everything that has been taught in this unit: Nuclear decay, practical applications of nuclear chemistry and fission and fusion.
This lesson show students that Energy and Matter are part of nuclear chemistry by comparing their understanding of fission and fusion with that of other students. They also read a ChemMatters article on nuclear decay that shows them that nuclear chemistry has practical applications in everyday life.
There are no Science and Engineering Practices incorporated into this lesson.
The past two days my students worked on a poster project that had students compare and contrast fission and fusion. They worked in groups of two and had to show the energy (input and output) involved in each process, the major isotopes involved and a real world example of each. Today they will compare their projects with other groups by performing a gallery walk.
At the very beginning of class I tell them to get their poster and find a space on the wall where they can hang their poster. I find that this works best by having one student get tape and the other person get the poster and finding a spot to hang the poster. After several minutes I have them go back to their seats and provide them with the day’s lesson. This inspires curiosity which engages students later in the lesson when they perform a gallery walk critiquing other groups' posters.
While groups are hanging their posters I hand out the ChemMatters article, “Radioactivity: It’s a Natural,” and the questions that go with the reading Since this reading assignment is acting as a review for the test, I modified many of the questions that ChemMatters offers to accompany the article and added several others that assess student understanding of radioactive decay and their ability to perform a decay series.
I tell students that the article on average should only take about 10-15 minutes to read since it’s only 2 1/2 pages in length; however, the questions will take another 10-15 minutes. One strategy I always tell my students is to briefly look over the questions before reading, this way they will have an idea of what information from the article will be needed to answer the questions. This combined with providing highlighters for the students that want them helps students focus on the reading in a more efficient manner.
In addition I tell students to pay close attention to question 4 because they have to write a decay series for the substance found in a smoke detector. This can be tricky because the article does not specifically say that decay is occurring, it just mentions that Americanium-241 is a source of alpha emission. This terminology is not typically what I use to describe decay, so some students struggle without a little clarification. I also tell them to pay attention to question 6 because they will need to perform a decay series for the isotope found in an electric blanket. The article only provides the isotope, so they need to locate the isotope in the reading and follow the series of decays provided in the question.
After most students have finished reading the article I let them work with a partner (sitting next to them) answering the questions (student work).
The goal of them reading the article was not only to incorporate reading and higher-order thinking into review, but to insure that students comprehend how decay occurs, what can block radioactive decay and what are real world applications for nuclear decay.
The last 15 minutes of students will perform a gallery walk viewing the posters that were hung at the beginning of the period. The purpose of this is to provide students with a look at other students work while comparing and contrasting their comprehension of fission and fusion with other groups.
While they are performing the gallery walk they are instructed to write down 3 similarities from three different posters, 3 differences they observed and how they are different from theirs and 3 improvements other groups could have made to provide more information. This is written on the back side of the reading question sheet. I encourage them to look at as many posters as possible, so that they can review as much as possible before the test.