Following up on the Lesson 27 pre-lab from yesterday, students were tasked with thinking through their setup and identifying one variable to manipulate in the lab today that would yield observable results (the responding variable).  Such manipulated variables included battery type, direction of current flow, choice of metals, and concentration of acetic acid.  Students had the remainder of the class period to set up their experiments, record observations, refine if necessary, and repeat yesterday’s experiment if insufficient data was recorded yesterday.  This work will be written into a lab report next week.