Understanding nature of science (NOS) is a fundamental goal in science education standards. Due to the role of specialised and educational teachers' preparation programmes in developing their NOS concepts, this study aims to identify views on NOS and attitudes toward teaching NOS among Saudi undergraduate chemistry students and the differences…

Learning about the nature of science is an important aspect of becoming part of the culture of practicing physicists. While these topics have a long-standing tradition in U.S. curricula they are currently not part of German educational standards or curricula. And while there is some research concerning primary and secondary school students'…

This paper aims to provide a contribution to the research in physics education regarding the interplay between mathematics and physics in teaching and learning physics at the university level. The argument is developed through a study focused on the historical case study of the blackbody that led Planck to make one of the most significant…

This article describes a combined UV-photometer and fluorimeter constructed from 3 LEDs and a few wires, all held in place with Lego bricks. The instrument has a flexible design. In its simplest version, two UV-LEDs (355 nm) are used as light source and to detect absorption, and a third LED, in the visible spectrum (e.g., 525 nm), is used to…

This work describes an effective, low cost method to anodize small aluminum objects. The use of a PVC spacer between the anode and cathode significantly reduces the size of the electrochemical cell and electrolyte required for its operation. Students will explore the physical and chemical properties of aluminum and anodized aluminum. They will…

Almost all commercial quadrupole ICP-MS instruments use collision/reaction cells to either attenuate spectral interferences or shift the analyte of interest to an interference-free "m/z" (e.g., by O addition). A laboratory practical was developed to introduce the students to the basic operating principles of ICP-MS using a hands-on…

A signature of life is that biological molecules occur as a single stereoisomer with respect to each chiral center, and this is echoed in the structures of biological polymers. Thus, circular dichroism (CD) has emerged as a hallmark of biomolecular structures. The tangible and familiar phenomenon of raw egg white's conversion from transparent…

Solubility is frequently introduced at the high school and introductory college levels through the symbolic domain using net ionic equations and solubility product constants. Students may become proficient with spectator ion cancellation and skilled with algorithmic mathematical applications of solubility without obtaining a deeper understanding…

An inversion polymorphism of the filamin and emerin genes at the tip of the long arm of the human X-chromosome serves as the basis of an investigative laboratory in which students learn something new about their own genomes. Long, nearly identical inverted repeats flanking the filamin and emerin genes illustrate how repetitive elements can lead to…

iSchlenk, a portable instructional cart with equipment for hands-on student experience in safe handling of air-sensitive, moisture-sensitive, toxic, pyrophoric, and/or radioactive chemical materials, is described. The cart, for use by =4 students, has compressed air and vacuum from a diaphragm vacuum pump supplied to 4 three-port Schlenk lines…

Chemical kinetic experiments to determine rate laws are common in high school and college chemistry courses. For reactions involving a color change, rate laws can be determined experimentally using spectrophotometric or colorimetric equipment though this equipment can be cost prohibitive. Previous work demonstrated that inexpensive handheld camera…

Necessary and sufficient criteria for reaction spontaneity in a given direction and for spontaneity of finite transformations in single-reaction, closed systems are developed. The criteria are general in that they hold for reactions conducted under either conditions of constant T and p or constant T and V. These results are illustrated using a…

A low-cost experiment to carry out the second-order reversible reaction of acetic acid esterification with ethanol to produce ethyl acetate is presented to illustrate concepts of kinetics and reactor modeling. The reaction is performed in a batch reactor, and the acetic acid concentration is measured by acid-base titration versus time. The…

A straightforward and inexpensive laboratory experiment is presented that investigates the physiological stress response of zebrafish after a 5 degree C increase in water temperature. This experiment is designed for an undergraduate physiology lab and allows students to learn the scientific method and relevant laboratory techniques without causing…

Organic reactions in introductory organic chemistry courses are most commonly taught with a mechanism-based approach to the understanding of molecular reactivity. However, the effectiveness of the popular curved arrow representation to describe reaction mechanisms is often compromised by the overuse of shortcuts and obscure notation. The…