A crystal model laboratory exercise is presented that allows students to examine relations among the microscopic-macroscopic-symbolic levels, using crystalline mineral samples and corresponding crystal models. Students explore the relationship between solid-state structure and crystal form. Other structure-property relationships are explored. The…

In this experiment the carotenoid bixin is isolated from annatto ("Bixa orellana") seeds using column chromatography. The experiment has several key advantages over previous pigment separation experiments. First, unlike other experiments significant quantities of the carotenoid (typically 20 to 25 mg) can be isolated from small quantities of plant…

The iodochlorination of styrene, involving the addition of iodine monochloride to styrene, followed by the sodium methoxide-initiated dehydrohalogenation of the product results in a variable mixture of substituted styrenes by way of various substitution and elimination reaction mechanisms. As a result individual results are obtained for each…

The fundamental and overtone vibrational absorption spectroscopy of the C-H unit in CHCl[subscript 3] is measured for transitions from the v = 0 energy level to v = 1 through v = 5 energy levels. The energies of the transitions exhibit a linearly-decreasing spacing between adjacent vibrational levels as the vibrational quantum number increases.…

Stockholm House of Science, focusing on astronomy, biotechnology and physics for students and teachers at school, is based on the proven concept of Stockholm Science Laboratory, which was mainly devoted to physics. The House of Science has become a popular and important resource and meeting place for teachers and students, stimulating interest in…

An educational set-up for cosmic ray physics experiments is described. The detector is based on scintillator tiles with a readout through metal resistor semiconductor (MRS) avalanche photo diode (APD) arrays. Typical measurements of the cosmic angular distribution at sea level and a study of the East-West asymmetry obtained by such a device are…

This article explores how to analyze and conceptualize the dynamics through which conversations in Change Laboratory research interventions lead to envisioning and implementing material changes in activities. Leont'ev's concept of personal sense is used as a theoretical lens for tracing these dynamics and to provide a means to relate local…

Not so long ago a new observation about rolling motion was described: for a rolling wheel, there is a set of points with instantaneous velocities directed at or away from the centre of the wheel; these points form a circle whose diameter connects the centre of the wheel to the wheel's point of contact with the ground (Sharma 1996 "Eur. J. Phys."…

This experiment presents a guided-inquiry approach to the demonstration of diastereoselectivity in an undergraduate organic chemistry laboratory. Chiral hindered ketones such as estrone, undergo facile reduction with sodium borohydride in a highly diastereoselective manner. The diastereomeric estradiols produced in the reaction can be analyzed and…

The text seeks to help students reach, through about 90 hours of class instruction, to acquire a level of competency necessary to repair a piece of laboratory equipment or construct a simple piece of equipment. Tools are introduced as needed in each of three sections of the text: (1) woodwork and metalworking; (2) electronic circuits; and (3)…

Success or failure of a language laboratory is due to a complex set of reasons. An often neglected factor lies in teacher and student attitudes to learner-machine-materials interrelationships. This paper specifies significant factors affecting the establishment of positive attitudes in teachers and students through training. The paper has four…

The complexity of today's research laboratories requires a completely controllable environmental surrounding. Research facilities require carefully controlled temperatures, relative humidity, and moisture, and must be free of interference from air-borne sound, mechanical vibrations, and electrical sources. Also desirable are special power…

Expresses concern over recent actions by coalitions of neighborhood activists and animal rightists in the San Francisco area that are seeking to block new biology laboratories. Argues that costly delays and disurption of research could result. (TW)

Offers challenging work at a higher level of technique than most students meet in elementary laboratory work. Uses a combined weight and volumetric sequence not shown in textbooks. Notes modern rapid balances help lower evaporation loss during weighings. Discusses the balance, weights, and buoyancy considerations. (MVL)

Notes that this experiment takes safety and noncarcinogenic reactants into account. Demonstrates the use of diazonium salts for the replacement of an aromatic amine group by a phenolic hydroxyl. Involves two pleasant-smelling organic compounds, methyl anthranilate (grape) and methyl salicylate (oil of wintergreen). (MVL)