Physical And Chemical Changes
December 5, 2017
You want an argument, bring some evidence!
What do students look for when they are trying to distinguish a physical change from a chemical change? Sure, things like a change in temperature, color, or the formation of bubbles are typical signs of a chemical change, but often those indicators are not enough. What other evidence can students site as they try to determine if a reaction has occurred?
To move beyond qualitative observations, they can collect data on the substances before and after they are combined. In this activity, students are given four beakers. In addition to visual observations, with the additional of sensors they can collect pH, temperature and conductivity data to analyze and interpret.