Nitrate is a crucial parameter for assessing water quality, owing to its dual function in ecological systems. These functions can be beneficial or detrimental depending on whether nitrate concentrations are low or high, respectively. The ultraviolet spectrophotometric method (standard as 4500-NO[subscript 3]--B) is a classic method for determining…

The objective of this work was to evaluate the implementation of a metavisual strategy for students to revise and self-regulate concepts arising in a study of a chemical reaction between ions. For this purpose, two chemistry education undergraduate students at a Brazilian public university carried out an investigative activity, involving…

Students' difficulties in quantum mechanics may be the result of unproductive framing and not a fundamental inability to solve the problems or misconceptions about physics content. We observed groups of students solving quantum mechanics problems in an upper-division physics course. Using the lens of epistemological framing, we investigated four…

This article revisits the cognitive load theory to explore the use of worked examples to teach a selected topic in a higher level undergraduate physics course for distance learners at the School of Distance Education, Universiti Sains Malaysia. With a break of several years from receiving formal education and having only minimum science…

Large gender gaps in performance on questions involving projectile motion have been observed at high school and university level, even amongst high-achieving students. This gap is particularly problematic because projectile motion is typically one of the first topics formally taught in physics, and this may give girls an inappropriately negative…

Early in their chemistry education, students learn to do empirical formula calculations by rote without an understanding of the historical context behind them or the reason why their calculations work. In these activities, students use paperclip "atoms", construct a series of simple compounds representing real molecules, and discover,…

What follows are several investigations involving string musical instruments developed for and used in a "Science of Sound & Light" course. The experiments make use of a guitar, orchestral string instruments and data collection and graphing software. They are designed to provide students with concrete examples of how mathematical formulae, when…

An approximate scheme for obtaining the period of a simple pendulum for large-amplitude oscillations is analysed and discussed. When students express the exact frequency or the period of a simple pendulum as a function of the oscillation amplitude, and they are told to expand this function in a Taylor series, they always do so using the…

The generalized second-order partial derivatives of 1/r, where r is the radial distance in three dimensions (3D), are obtained using a result of the potential theory of classical analysis. Some non-spherical-regularization alternatives to the standard spherical-regularization expression for the derivatives are derived. The utility of a…

For beginning chemistry students, the basic tasks of writing chemical formulas and naming covalent and ionic compounds often pose difficulties and are only sufficiently grasped after extensive practice with homework sets. An enjoyable card game that can replace or, at least, complement nomenclature homework sets is described. "Go Chemistry" is…

Describes two easily applied mathematical theorems, Budan's rule and Rolle's theorem, that in addition to Descartes's rule of signs and intermediate-value theorem, are useful in chemical equilibrium. Provides examples that illustrate the use of all four theorems. Discusses limitations of the polynomial equation representation of chemical…

Discusses formal-economical/epistemic-powerful features of physics formulas: the first puts constructs in logical relations to each other, reducing constructs to symbols; the second describes the correspondence which links the construct to natural events. Implications of the dual nature of formulas (considered as efficient learning tools) for…

Presented is a photoelectric colorimeter which can be assembled by the student. Reports that it can do many of the same analyses as the SPEC 20 but at a greatly reduced cost using older technology. Presents several experiments to use with the colorimeter. (MVL)

Describes two chemistry computer programs: (1) "Eureka: A Chemistry Problem Solver" (problem files may be written by the instructor, MS-DOS 2.0, IBM with 384K); and (2) "PC-File+" (database management, IBM with 416K and two floppy drives). (MVL)

Suggests an approach to understanding the integrals associated with teaching electricity and magnetism at the college level. Categorizes integrals that are commonly used, explains the significance of paired usage and presents a method for introducing concepts. Provides a review of symbols and for integrals in college textbooks. (CW)