The stoichiometry of the reaction between potassium chromate and barium chloride is determined by analysis of precipitates by mixing various amounts of both solutions. (GS)

Describes an experiment in which the beam of X-rays is simulated through the use of a laser as a monochromatic light source and the crystal is replaced by photographically prepared masks. A strong diffraction pattern as large as 20 cm. can be obtained. (GS)

Presents a simple method of analysis in which the student can integrate, point by point, any interferogram to obtain its Fourier transform. The manual technique requires no special equipment and is based on relationships that most undergraduate physics students can derive from the Fourier integral equations. (Author/MLH)

Discusses the planning and implementation of a laboratory course in which students carried out experimental measurements, reduced data, conducted literature surveys, and presented their results in the form of original research papers. (Author/MLH)

In a Millikan oil drop experiment, there is a best measuring time for observing the drop, due to Brownian motion of the drop and the experimenter's reaction time. Derives an equation for the relative error in the measurement of the drop's excess charge, and obtains a formula for the best measuring time. (Author/MLH)

This study assesses the effect of speech-anxious subjects acting as behavior therapists for other speech-anxious subjects. Subjects were divided into helper, helpee, latent helper, and waiting list control groups. Both helpers and helpees significantly reduced speech anxiety. The helpers showed more absolute improvement than the other groups.…

Describes the experimental procedure and expected outcome in the growth of rice seedlings with light conditions and water aeration as variables. (GS)

Discusses minimum necessary nuclear fundamentals of radioactive isotopes such as levels of activity, specific activity and the use of carrier materials. Corrections that need to be taken into account in using an isotope to obtain a valid result are also described and statistics for a valid result are included. (BR)