Conservation of Matter

After reviewing the homework problems assigned for Lesson 7, students were reintroduced to the Copper Cycle.  Because the Copper Cycle experiment involves steps that must be conducted in a fume hood, we opted to watch a video (below), with students taking observations on their Copper Cycle handout.  For reference, students also received a copy of the Copper Cycle experimental procedure.

After the video, we discussed the concept of Conservation of Matter, transitioning to Lesson 8 in the textbook.  Because Lesson 8 continues an investigation of the Copper Cycle, and we are unable to safely conduct that lab, we instead investigated the related concept of Conservation of Mass.  Students participated in a classroom demonstration which involved combining baking soda and vinegar in a closed system and experimentally demonstrating that mass is conserved.  We measured the starting and ending mass, noting the slight decrease in mass at the end due to experimental error (vinegar and carbon dioxide leaking slightly).  At the end of the experiment, we removed the inflated balloon and noted a decrease in mass of 0.2-0.3 grams, indicating the carbon dioxide gas has a measurable mass.  Students also noted the change in volume of the products as evidenced by the partially inflated balloon compared with the volume of the reactants.

For homework, students were provided with a copy of the Penny Lab to read over in advance of Wednesday’s class.  Students were also reminded that a signed syllabus and safety contract must be turned in to enable participation in the lab.

Materials, Mass, and Volume
Chemical Reaction


Framework for Ethical Decisions

With textbook checkout taking a bit longer than anticipated on Friday, we began the week by finishing Friday’s lesson with students  taking notes on the Principles of Bioethics.  We then discussed the concept of a stakeholder, a person with an interest or concern in something.

We revisited the issue of people choosing not to have their children vaccinated (introduced on Friday) by watching another short video from Frontline (below).  Students were tasked with writing down a list of the stakeholders they observed in the news segment.

After the video, we created a class list of stakeholders and students used the list to help them fill out the Focus on the Principles worksheet with the ethical question of “Should healthy people choose not to be vaccinated?”  After some private think time, we shared out as a class and answered questions about the Principles of Bioethics.  Students were instructed to keep the worksheet as a resource to use in tomorrow’s work.

To conclude the lesson, students received a copy of the Rezip Case Study to read in class.  Students were assigned to complete the reading as homework if additional time outside of class was needed.

Optional additional learning opportunities (click the links):

US Dept of Health & Human Services definition of herd immunity

US Centers for Disease Control and Prevention (CDC) FastStats page for Measles, Mumps, and Rubella

Washington State Department of Health – certificate of exemption (note the provider section)

SciShow follow-up video about “The Science of Anti-Vaccination”

NOVA | Vaccines –– Calling the Shots | PBS – a video examining the science behind vaccinations, the return of preventable diseases, and the risks of opting out