An approach is described in which accurate weighings are provided under circumstances when samples cannot be placed directly on a balance pan. The approach, based on external weighing, uses a new simple apparatus designed for any kind of analytical balance and not requiring a hole through the base of the balance. (JN)

A quantitative determination for fluoride ion using a commercially available fluoride electrode is described. The procedure referred to as known-addition is employed with the data processed on Gran's Plot Paper. Background information, experimental procedures, and advantages/disadvantages of the method are discussed. (JN)

The main problem in constructing functioning electric motors from simple parts is the mounting of the axle (which is too flimsy to maintain good electrical contacts or too tight, imposing excessive friction at the supports). This problem is solved by using a pencil sharpened at both ends as the axle. (JN)

Describes a low-cost, senior-level, instrumental analysis experiment in which a home-made potassium tubular flow-through electrode is constructed and incorporated into a flow injection analysis system (FIA). Also describes experiments for evaluating the electrode's response properties, examining basic FIA concepts, and determining potassium in…

Basic concepts associated with seismic wave propagation through the earth and the location of seismic events were explained in part 1 (appeared in January 1983 issue). This part focuses on the construction of a student seismometer for detecting earthquakes and underground nuclear explosions anywhere on the earth's surface. (Author/JN)

Thermal features of and beneath the surface of a sample can be detected and imaged with a thermal-wave microscope. Various methodologies for the excitation and detection of thermal waves are discussed, and several applications, primarily in microelectronics, are presented. (Author)

Desorption ionization (DI) is used to obtain mass spectra of molecules whose vaporization by heating may lead to thermal degradation. Discusses DI techniques, characteristics of DI mass spectra, ion production, current applications of DI in mass spectroscopy, developments in DI, and prospects for future evolution of new DI techniques. (Author/JN)

The kinetic of the Jaffe reaction with picrate ion selective electrode (ISE) and a kinetic method for determining creatinine in urine is presented. The experiment could be used to familarize students with the application of ISE in kinetic studies and chemical analysis. (Author/JN)

Suggestions for successful geology field trips are provided. These "field hints" focus on geological reasoning; equipment; notes; samples and records; field practices, including mapping; camping; working with associates in the field; and general considerations such as carrying along a few textbooks, finding out about an area before the trip, and…

Instructions for constructing cross staffs and quadrants are provided. Astronomy teaching methods using the two devices are discussed. These include locating common constellations with the cross staff and following a star (or moon, sun, or planets) by reading the altitude and azimuth with the quadrant. (JN)

Physicists had assumed that the world is distinguishable from its mirror image and constructed theories to ensure that the corresponding mathematical property (parity) is conserved in all subatomic processes. However, a scientific experiment demonstrated an intrinsic handedness to at least one physical process. The experiment, equipment, and…

Although most waves studied by students satisfy the linear equation, particle physicists have become interested in nonlinear waves--those not satisfying the superposition principle. A mechanical wave system, satisfying the sine-Gordon equation, can be constructed using a modified transverse wave system to demonstrate nonlinear wave-particle…