Difficulties in teaching the concepts
of ‘amount of substance’ and ‘mole’

Carlos Furio, Department of Didactics of Experimental and Social Sciences, University of Valencia, Rafael Azcona, ‘Talaia-Hondarribia’ High-School, Jenaro Guisasola, Department of Applied Physics I, University of the Basque Country, Spain and
Mary Ratcliffe, Research and Graduate School of Education, University of Southampton, UK