This article shows that, by applying the Hellman-Feynman theorem alone to screened Coulomb potentials, the first four coefficients in the energy series in powers of the perturbation parameter can be obtained from the unperturbed Coulomb system. (Author/HM)

Discusses the nature of the impurity modes in a monatomic chain employing a molecular mode. This approach brings out clearly the characteristics of the inband, localized, and resonant modes of substitutions impurities in crystals. (Author/HM)

Describes a method to determine the thermal diffusivity of a polymer, which is suitable for the undergraduate laboratory. It serves as a practical demonstration of classical Fourier theory. (Author/HM)

Included is information regarding: fabrication of light emitting diodes, their operation as semiconductors, and an experiment demonstrating electroluminescence; experimenting with Random Access Memory (RAM) circuits; demonstrating Coriolis effect; measuring the diameter of an electron beam, E.H.T. meters; launching a trolley by catapult; a "random…

Formative evaluation of a physics curriculum unit (PLON) is reported. Phase one used general ideas and many instruments; phase two focused on specific questions arising from phase one. Findings suggested that relating curriculum content to ability to think about and explain a task was a prerequisite for student satisfaction. (CP)

Describes a general purpose algorithm which enables one to calculate the allowed energy eigenvalues for an arbitrary potential. Results of a calculation where a centrifugal potential is added to the hydrogenic Coulomb potential are discussed. (Author/HM)

Describes the use of transistors instead of valves for Lecher line and radiation demonstrations. Two oscillator circuits which provide power for Lecher line use are described. Impedance of Lecher line is also discussed. (HM)

It is shown that exact pseudopotentials for excited states of hydrogen atoms can be derived. A very simple, novel application of pseudopotential method which displays vividly some of its limitations is presented. (Author/GA)

Explains how to use magnetic cylinders on an air table to demonstrate certain atomic structure and vibrational behavior in many face-centered metals like aluminum or copper. (GA)

Details the personal experiences, accumulated over a 25-year teaching career, of a physics teacher at a private boarding school in New England. (BT)

Described is the use of an interactive terminal-oriented computing system that has access to files of thermodynamics data. (Author/SA)

Describes a scheme for teaching physics in secondary schools. Included is a brief description of the scheme as it was tested in a Yugoslavian secondary school. (SA)

Describes the use of interviews with children ranging in age from 6 to 13 to identify patterns of children's beliefs in the area of heat and temperature. Also discusses how this knowledge might be used in an instructional setting. (HM)

Explains the origins of quasi-history in physics, and its aims of providing a framework for relevant scientific facts. Presents a large number of examples and discusses their effects on attitudes of students and others toward physics and science in general. (GA)

Presents a nuclear power plant simulation game which is designed to involve a class of 30 junior or senior high school students. Scientific, ecological, and social issues covered in the game are also presented. (HM)