Examines the controversy surrounding the validity and interpretation of electron microscope images. (DS)

Describes a means of collecting evolved gases which overcomes the usual disadvantages experienced in covering the electrodes with test tubes full of electrolyte solution. (GS)

Describes: (1) a microcomputer demonstration of autocatalysis; (2) a safe alternative to ethanol and methanol; (3) a simple condenser for test-tube reactions; (4) a new procedure for studying the magnetic properties of transition metal compounds; (5) plasticization of the polymer PVC; and (6) some thoughts on polybasic acids and their salts. (JN)

Describes an experiment suitable for high school physics classes in which students determine the wavelength of electromagnetic radiation of u.h.f. television transmissions. Elaborate equipment is not required, and details are given for the construction of a dipole. (JR)

Outlines what a hologram is, the main types of holography, and how a simple system producing a white light reflection hologram can be set up in a school physics laboratory. Discusses the basic optics of the hologram and procedures and materials for making holograms in school. (YP)

Describes the construction of a model suitable for demonstrating the principles of refrigeration in secondary science classes. (JR)

The first part of a two-part article describes an experimental approach that can be used in teaching the concept of saturated vapour pressure. This leads to a discussion of refrigeration cycles in the second part of the article. (JR)

Lists 25 energy activities and describes two experiments (materials needed and procedures used included) for secondary/middle school students. Like activities for younger children listed in part 1 (appearing in Vol. 65, No. 229), these activities are designed to provide concrete experiences for teaching various aspects of the energy concept. (JM)

Outlines a variety of laboratory procedures, techniques, and materials including construction of a survey frame for field biology, a simple tidal system, isolation and applications of plant protoplasts, tropisms, teaching lung structure, and a key to statistical methods for biologists. (DS)

Outlines several laboratory procedures and demonstrations including electric fields using sawdust, experiments with capacitors, particle spacing in a vapor and a liquid, metrology, momentum, Moire patterns and interference fringes, equipping for practical electronics, and using programmable calculators for rapid plotting of graphs. (DS)

Presents procedures, demonstrations, activities, and teaching suggestions on topics appropriate for middle school science including a simple electrolysis cell, conversion factors, energy, solubilities of salts, condensers, and a worksheet for studying coppice woodlands. (DC)

Discusses determination of elliptical path of a satellite caught into orbit by the sun or earth; using microcomputer as signal generator (includes program listing); collision process; simple hysteresis loop using double beam CRO; method of demonstrating parallelogram of forces; measuring radius of electron beam curvature; and half-life of thorium…

Discusses dice model of exponential radionuclide decay; glancing and collinear perfectly elastic collisions; digital capacitance meter; use of top pan balance in physics; microcomputer calculation of gradient of straight line (includes complete Commodore PET computer program); Fresnel lenses; low-voltage radiant heater; Wheatssone's bridge used as…

Presents chemistry experiments, laboratory procedures, demonstrations, and classroom materials/activities. These include: experiments on colloids, processing of uranium ore, action of heat on carbonates; color test for phenols and aromatic amines; solvent properties of non-electrolytes; stereoscopic applications/methods; a valency balance;…

Presented are physics experiments, laboratory procedures, demonstrations, and classroom materials/activities. Experiments include: speed of sound in carbon dioxide; inverse square law; superluminal velocities; and others. Equipment includes: current switch; electronic switch; and pinhole camera. Discussion of mechanics of walking is also included.…