Newton's law of cooling describes an object whose temperature decreases exponentially with time. Because of its many applications, it is a frequent topic of introductory physics labs. In this article, I describe an experiment designed for the freshman year algebra-based physics course that applies this law to answering the question, "Why…

"N"-Formamides are important intermediates in the synthesis of many pharmacologically active compounds and are used as protecting groups for amines or as catalysts in different reactions. The current "N"-formylation experiment is designed as a part of an introductory organic chemistry course for undergraduate students. The…

The ability to understand the relationship between the reversal potential and the membrane potential is a fundamental skill that must be mastered by students studying membrane excitability. To clarify this relationship, we have reframed a classic experiment carried out by Hodgkin and Katz, where we compare graphically the membrane potential at…

In an ever-changing environment, survival depends on learning which stimuli represent threat, and also on updating such associations when circumstances shift. It has been claimed that humans can acquire physiological responses to threat-associated stimuli even when they are unaware of them, but the role of awareness in updating threat…

Water electrolysis, a well-known and simple experiment, confirms that a water molecule comprises hydrogen and oxygen atoms. In this experiment, hydroxide or hydrogen ions generated from each electrode were identified using an indicator based on the assumption that electrodes, electrolytes, and indicators do not participate in the water…

We have expanded Stein's "Sweetness of Aspartame" laboratory project (Stein, P. J. "J. Chem. Educ." 1997, 74, 1112, DOI: 10.1021/ed074p1112) to include extensive use of statistical testing. Students test the statistical significance of a nonzero intercept in a linear regression, bias in comparison to a true value, and…

Cell size is an important variable in the study of cellular growth, metabolism, and the cell cycle. The large size of "Amoeba proteus" and the ease with which it can be collected and cultured have made it a star in biology education--and it was a model for research on cell biology before the introduction of molecular genetic methods.…

A simple method is described for measuring liquid density based on stretching of the spring and equilibrium of weight and elastic force. The method involves placing a container with liquid under test on the spring causing a stretch of the spring that is directly proportional to the weight of the liquid. With this technique, the liquid density can…

A solar eclipse provides a well-characterized reduction in solar radiation. Solar radiation is a driving factor in meteorological and climate models. Hence, solar eclipses provide a unique opportunity to do large-scale meteorological experiments by measuring the effects on temperature, pressure, and wind while the atmospheric conditions stay…

The majority of chemical experiments conducted during educational programs are carried out in laboratories because they require instructors with special skills, in addition to large, expensive instruments. Recently, there has been an increasing demand for chemical experiments that can be carried out anywhere. Herein, we propose a novel type of…

This study proposes a lab experiment consisting of three consecutive steps designed to expose undergraduate students to the fundamental aspects of nanoscience. Two different procedures for the reduction of silver ions were provided: Th was obtained. Next, the students explored the aggregation process of silver nanoparticles by converting one…

Studying the dynamics of beams is considered an indispensable field for mechanical and civil engineering students. This paper describes, in detail, the use of smartphones in educational practical works to determine and examine the dynamic characteristics of beams subjected to free vibration. Where the smartphone is equipped with a mobile…

Although it originates from the ancient Greeks, optics still arouses a lot of scientific interest, mainly due to the technological innovation associated with it. One of its most interesting applications is related to optical metrology and the characterization of materials through optical techniques. While some of these processes can be explained…

A straightforward experimental set-up, requiring a two-liter bottle, a ruler and a stopwatch, is used to provide data appropriate for modelling with Torricelli's Law in the simplest case, and a more sophisticated differential equation when losses are taken into account and a pipe extension is considered. With only an exit hole included in the…

As a model study for improving undergraduate organic chemistry laboratories with contemporary research concepts and practices, we evaluated a project module aiming at the synthesis of two porphyrin compounds. The module was implemented in a format that differed in several ways from that of a traditional course. It was designed for small student…