This study uses graphs of conductivity measured by a microcomputer-based laboratory (MBL) to promote students' macro, micro, and symbolic representations when learning about net ionic reactions (NIR). A total of 54 students, aged 14-15 years old participated in this research, and were randomly divided into an experimental group (N = 27) and a…

Electrocardiography (ECG) is one of the most widely used methods in clinical diagnosis. Here we describe an experimental approach that offers hands-on learning of its basic principles. An experimental model that consists of a rubber foil with a low electrical conductivity and a DC power unit is used to simulate the body and the electric dipole of…

The paper describes a set of physics demonstration experiments where thermal sensitive foils are used for the detection of the two dimensional distribution of temperature. The method is used for the demonstration of thermal conductivity, temperature change in adiabatic processes, distribution of electromagnetic radiation in a microwave oven and…

Periodic conductivity trends are placed in the scope of lithium-ion batteries, where increases in the ionic radii of salt components affect the conductivity of a poly(ethyleneoxide)-based polymer electrolyte. Numerous electrolytes containing varying concentrations and types of metal salts are prepared and evaluated in either one or two laboratory…

The classic technique for sulfate analysis in an undergraduate quantitative analysis lab involves precipitation as the barium salt with barium chloride, collection of the precipitate by gravity filtration using ashless filter paper, and removal of the filter paper by charring over a Bunsen burner. The entire process is time-consuming, hazardous,…

Providing instant visual feedback, thermal imaging cameras are becoming more and more popular tools not only in industrial applications, but also in physics education. Continuously decreasing prices, modules compatible with smart portable devices, and intuitive operation make thermal measurements available for schools and attractive for students.…

Magnetic braking is a long-established application of Lenz's law. A rigorous analysis of the laws governing this problem involves solving Maxwell's equations in a time-dependent situation. Approximate models have been developed to describe different experimental results related to this phenomenon. In this paper we present a new method for the…

Describes apparatus for use in high school chemistry instruction. Provides instructions and lists of materials needed for building a homemade sand bath for use in experiments that demonstrate the slow evaporation of a solvent. Plans for the construction of a low-cost conductivity apparatus are also included. (TW)

Presents a laboratory experiment which illustrates the formation of tris(phenanthroline)cobalt complexes in the 2+ and 3+ oxidation states, the effect of coordination on reactions of the ligand, and the use of a ligand displacement reaction in recovering the transformed ligand. Uses IR, UV-VIS, conductivity, and NMR. (MVL)

Presents a low cost system with easily replaced electrodes for use in general chemistry. Notes the accuracy and wide applicability permit easy use in physical or quantitative chemistry experiments. Provides schematic, theory, and helpful suggestions. (MVL)