The pencil-and-paper assignment "Represent water in its three states using a model" was given to pupils (n=227) from eighth to twelfth grades. The findings show that the dominant model used was the space filling type; movement of particles was indicated by a minority of pupils; size of the model changed when drawn in different states.…

Analytical methods are reviewed for: alkali and alkaline earth metals; transition metals; precious metals; group 12, 13, 14, and 15 metals, nonmetals; radionuclides; multiple metals; anions; gases; chromatography; mass spectroscopy; photometry; sampling; volatile compounds; surfactants; detergents; pesticides; herbicides; and fungicides. (MVL)