Charity Flener Lovitt (Seattle University, USA)
In developing an atoms first course, one of the hardest aspects to adapt is the lab sequence. In traditional lab sequences, students use stoichiometry to verify the reactivity of known compounds. However, in an atoms first approach, students may not learn chemical stoichiometry until 6 weeks into the course. An atoms first curriculum gives the instructor the opportunity to use discovery based labs where students collect data and analyze trends before they see the material in class. For example, to learn about covalent and ionic compounds, students run an electrical current through solutions. They are told the formula of the compound in the solution. Students are then asked to group the compounds according to the amount of electricity they conduct. They then use the molecular formulas to determine why some compounds are conductive (ionic) and others are non-conductive (covalent or weakly ionic). They complete this experiment before learning about ionic and covalent bonding. Current research shows that students retain knowledge longer when they use this constructivist approach.