Natural sciences can be difficult to grasp because physical and chemical phenomena can take place across time and length scales that are beyond the reach of human perception. This problem is particularly true for students attempting to learn about microfluidics, a discipline that involves intricate engineering methods and fluid phenomena that are…

Although unrecognized for his scientific achievements during his life, Gregor Mendel pioneered our modern understanding of the gene, work that shaped the field of genetics and advances in biology and medicine. The field that he set in motion 200 years ago lies at the center of current ethical debates about the future of humanity, the limits of…

The refractive index is a number that governs how light changes its direction of propagation as it enters one material medium from another. This phenomenon is known as refraction and the angles of incidence and refraction of light, referred to the normal to the interface of the two media at the point of incidence, are related by Snell's law. The…

Redox reaction is a core concept in teaching and learning chemistry. This article explores a new method for balancing organic redox reactions that requires the balancing of both atoms and charges. The H+, O, H[subscript 2]O, and e- are used as balanced vehicles in two half reactions. A non-oxidation number approach can be applied to both molecular…

Morphology-dependent properties are significant in chemistry and material sciences. This laboratory experiment, designed for upper-division undergraduates in chemistry and related majors, emphasizes the concepts of the shape-controlled synthesis of crystal particles and the influences of crystal particle morphologies on their reaction…

The interference pattern between two harmonic oscillations with slightly different frequencies are called beats. The beats, as a combined motion, have two different periods, one approximately equal to the period of the original oscillations, and another that is significantly longer and is related to the variable amplitude of the motion. The main…

Oxidation number (ON) is taught as an electron-counting concept for redox reactions in chemistry curriculum. The molecular formula method, the Lewis formula method, and the structural formula method have all been used to determine ON. However, the task of assigning ON still poses problems for some teachers and students. This paper explores a new…

In this article, we construct a very simple double pendulum (the concept of a pendulum should be familiar to all beginning students of classical mechanics). Since a double pendulum has two degrees of freedom, we suggest that this pendulum can be used in the classroom environment to illustrate the concept of normal modes, and we use video software…

The reflection and refraction of light are more familiar to students than the reflection and refraction of sound. Reflection and refraction that occur during the transmission of sound waves are common phenomena in everyday life but are often difficult to understand during actual learning. In this study, we developed a sound reflection and…

The weight, one of the key concepts of physics education, still continues to be discussed among physics educators. Today, there are two main definitions as the 'gravitational' and 'operational', but there are differences even between them. It is important to know the different approaches found in textbooks in eliminating misconceptions and…

Ever wonder how an astronaut's mass is measured in space? Of course, a weight scale is of no use, because the astronaut and the scale are in free fall. Measuring the period of a spring mass oscillator is one way to measure mass. In this article, we will demonstrate a method to measure mass using a smartphone, a rubber band, and an app called…

Teaching special relativity to lower-division students is challenging because results such as time dilation, length contraction, and frame dependence of simultaneity are counterintuitive. The literature is extensive, so only a brief list is given here, with articles divided roughly between discussions of general principles and calculations applied…

Recently I took a walk through the physics demonstration room at Kenyon College, where I first started teaching in 1964. On an upper shelf was the little home-built apparatus in Fig. 1. This was used for one of two short single-concept films that I made in the 1970s. Both "The Magnus Effect" and "Optical Barrier Penetration"…

We sought to improve concept application in introductory mechanics by emphasizing causal statements (such as "forces change momentum") instead of laws (such as [delta]p=F[delta]t). Using student performance on a well-documented question, this intervention showed modest improvements. However, students in classes using recently introduced…

A drama model can be helpful to support children's understanding of some of the more abstract parts of the science curriculum. The drama models can usefully enhance children's understanding of scientific processes and concepts. They can help to link the practical activities with the conceptual understanding. The use of more than one way of…