Integrating authentic research practices into introductory laboratory courses to prepare tomorrow's scientists has become increasingly prevalent over the past decade. However, an incomplete understanding of the nature of science (NOS) and authentic scientific inquiry (SI) precludes higher-level learning in undergraduate research experiences. In…

An instructional research-like multiweek laboratory project for a second-semester introductory general chemistry laboratory course has been developed. The ultrasonic-assisted synthesis method using low cost commercial ultrasonic cleaners has the convenience of running multiple students' reactions simultaneously. Taking advantage of short reaction…

Equilibrium is an essential concept in undergraduate physics curriculum as it integrates Newton's laws and torque. The importance also comes from its wide applications in mechanics and biomechanics. Simulations of Back and Arms are developed mainly for the undergraduates who major in physical therapy and health sciences. They are implemented as…

Scientific writing, in the form of lab notebooks, proposals, and reports, is a common element of physics lab classes. Multiweek student-designed projects are growing in popularity, especially in advanced lab courses, and writing may play a unique role in these types of courses. In prior work, we developed a framework of possible goals for writing…

The language of physics is mathematics, and physics ideas, laws and models describing phenomena are usually represented in mathematical form. Therefore, an understanding of how to navigate between phenomena and the models representing them in mathematical form is important for a physics teacher so that the teacher can make physics understandable…

In this paper, a discrepant event is used to initiate a learning cycle lesson to help students develop an understanding of the concept and equation for buoyant force. The data are gathered using readily available equipment and then graphically analyzed using a four-step analysis consistent with the modeling instructional approach. This laboratory…

A porphyrin-based test paper has been designed and prepared. It can be used to analyze for Al[superscript 3+] and Fe[superscript 3+] in aqueous solution. An experiment employing the test paper can help students understand basic principles of spectrophotometry and how spectrophotometry is used in analyzing for metal ions. (Contains 1 scheme and 1…

This article describes a simple and robust laboratory exercise on the regulation of membrane unsaturated fatty acid composition in bacteria by a decrease in growth temperature. We take advantage of the well characterized Des pathway of "Bacillus subtilis", composed of a [delta]5-desaturase (encoded by the "des" gene) and the canonical…

Chemoselectivity is a central concept in organic synthesis and may be readily appreciated in the context of the fragrant, polyfunctional natural product citral. We describe three single-step reactions students may perform on citral to synthesize other natural perfumes: citronellal, geraniol, nerol, or epoxycitral. Each of the reactions uses a…

In this laboratory experiment, students quantitatively determine the concentration of an element (mercury) in an environmental or biological sample while comparing and contrasting the fundamental techniques of atomic absorption spectrometry (AAS) and atomic fluorescence spectrometry (AFS). A mercury analyzer based on sample combustion,…

A wash bottle water displacement scheme is used to determine the kinetics of the iodide-catalyzed H[subscript 2]O[subscript 2] decomposition reaction. The reagents (total volume 5.00 mL) are added to a test tube that is placed in a wash bottle containing water. The mass of the water displaced in [approximately]60 s is measured. The reaction is…

An analytic approximation of the solution to the differential equation describing the oscillations of a simple pendulum at large angles and with initial velocity is discussed. In the derivation, a sinusoidal approximation has been applied, and an analytic formula for the large-angle period of the simple pendulum is obtained, which also includes…

This paper analyses the real origin and nature of scientific errors against claims of science critics, by examining a number of examples from the history of electricity and optics. This analysis leads to a conclusion that errors are a natural and unavoidable part of scientific process. If made available to students, through their science teachers,…

In the process of working through evaluation of efforts to transform undergraduate laboratory experiences at our institution, we developed a protocol for observing laboratory learning environments that could be used in varying institutional contexts. We began using the Instructional Practices Inventory and found many strengths in this protocol but…

We developed a modular pair of experiments for use in the undergraduate physical chemistry and biochemistry laboratories. Both experiments examine the thermodynamics of the binding of a small molecule, eosin Y, to the protein lysozyme. The assay for binding is the quenching of lysozyme fluorescence by eosin through resonant energy transfer. In…