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…

The present study describes the development and field testing of a simple apparatus-based diagnostic instrument (SABDI) that examines undergraduate students' understanding of the underlying physics principles that explain how simple acoustic apparatuses work. SABDI comprises 13 items. Based on previous research studies and the history of science,…

In this undergraduate analytical chemistry experiment, students quantitatively assess the antibacterial activity of essential oils found in thyme leaves ("Thymus vulgaris") in an authentic, research-like environment. This multi-week experiment aims to instill green chemistry principles as intrinsic to chemical problem solving. Students…

Physiology demands systems thinking: reasoning within and between levels of biological organization and across different organ systems. Many physiological mechanisms explain how structures and their properties interact at one level of organization to produce emergent functions at a higher level of organization. Current physiology principles, such…

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…

Flotation as a method of separation is widely researched and is applied in many industries. It has been used to address a wide range of environmental issues including treatment of wastewater, recovery of heavy metals for recycling, extraction of minerals in mining, and so forth. This laboratory attempts to show how such a simple method can be used…

It will be demonstrated how the reflection law may be derived on an atomic basis using the plane wave approximation together with Huygens' principle. The model utilized is based on the electric dipole character of matter originating from its molecular constituents. This approach is not new but has, since it was first introduced by Ewald and Oseen…

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…

Thin-layer chromatography (TLC) is one of the basic analytical procedures in chemistry and allows the demonstration of various chemical principles in an educational setting. An often-overlooked aspect of TLC is the capability to quantify isolated target compounds in an unknown sample. Here, we present a suitable route to implement quantitative…

The Force Concept Inventory is one of the most popular and most analyzed multiple-choice concept tests used to investigate students' understanding of Newtonian mechanics. The correct answers poll a set of underlying Newtonian concepts and the coherence of these underlying concepts has been found in the data. However, this inventory was constructed…

In the present article, the context-dependency of student reasoning is studied in a context of optics. We investigated introductory students' explanations about the behavior of light when different light sources, namely a small light bulb and a laser, were used in otherwise identical task assignments. The data was gathered with the aid of pretest…

The ray tracing method is widely used in teaching geometrical optics at the upper secondary and university levels. However, using simple and straightforward examples may lead to a situation in which students use the model of ray tracing too narrowly. Previous studies show that students seem to use the ray tracing method too concretely instead of…

At universities where introductory physics labs are taught by graduate student teaching assistants (TAs), there is a need for specialized professional development for those TAs. This paper presents a specific instantiation of a model for lab TA professional development that uses a combination of cognitive apprenticeship and expectancy-value…