Resumen de Those Baffling Subscripts
Arthur W. Friedel, David P. Maloney
Students in several college general chemistry courses were presented with a variety of paper and pencil tasks in two formats, multiple choice and ranking tasks. The tasks dealt with unit mass--either molar mass or gram atomic weight-- macroscopic mass, number of atoms in each molecule, and total number of atoms present. Students were given information about three of the four features/variables and asked about the fourth. Results showed that students had difficulty effectively using information about the number of atoms in a molecule, i.e., the information provided by the subscript in the chemical formula, in solving these problems. One interpretation of these results is that students have difficulty using subscript information effectively because they frequently fail to differentiate between atoms and molecules. Instructional alternatives for dealing with the difficulty are described.
