In this paper, an experimental setup composed of a color-mixing device, power supply, and spectrometer is developed. This setup is available for students to do hands-on color mixing with red, green, and blue light in undergraduate labs. LED volt-ampere and spectrum characteristics are investigated. The apparatus was used to perform additive color…

The area near the electrode surface is called the diffusion layer, and to understand electrochemistry, it is crucial that students have a knowledge of the phenomena occurring at the diffusion layer. Here, we present a demonstration and activity to visualize and analyze the expansion of a micrometer-sized diffusion layer. The electrode process…

What colors do you use in class when teaching electromagnetism? For many physics educators we simply use what we learned or what is used in the textbook. Browsing through a large collection of introductory physics textbooks reveals that the vast majority use red for the electric field, blue for the magnetic field, and some shade of green for the…

Chladni patterns are one of the most fascinating physics demonstrations. They can be produced very easily using commercially available apparatus based on metallic plates attached to a mechanical driver, similar to a loudspeaker without the membrane, and a signal generator. The figures are observed using sand sprinkled on the surface of the plate.…

The laser pointer has been widely used to demonstrate some simple optics phenomena, like reflection, refraction, total reflection, and diffraction. However, the rays of laser light cannot be seen in the air because the scattered light is too weak. Many physics teachers use milk or smoke to visualize rays of laser light in physics labs, but it is…

White light refracted by a glass edge or a prism might be split into the colors of the rainbow but, when restricted by a suitable arrangement of edges, might also yield a sequence of colors complementary to the rainbow. We studied the creation of these color fields experimentally with a setup consisting of RGB light-emitting diodes that cover all…

In this study, we describe a method to employ a conventional compound light microscope, usually available in laboratories, to obtain fluorescence. In particular, two pieces of colored acrylic plastic were utilized to assist the microscope in filter performance. We also attempted to examine the applicability of the setup by staining onion cells…

Many of us teach that insects can see "invisible" ultraviolet light, but what demonstrations do we perform to illustrate this? Often UV can be used to cause fluorescence or phosphorescence, which can make its existence more visible. But, is it possible to create photographs or videos that convincingly illustrate the vision of insects? In…

Diffraction is an important phenomenon in physics. This paper describes using a scanning electron microscope (SEM) to produce cross-sectional images of iridescent seashells. When seashell cross-sections are viewed in a SEM, regular structure is seen. Seashells are a good example of a biocomposite material and good natural objects for introducing…

Given the growing prevalence of computational methods in chemistry, it is essential that undergraduate curricula introduce students to these approaches. One such area is the application of machine learning (ML) techniques to chemistry. Here we describe a new activity that applies ML regression analysis to the common physical chemistry laboratory…

Additive colors are interesting to young students. In this paper, we show a convenient and straightforward method to demonstrate this phenomenon by projector. It produces defocus blur and reduces imaging quality for color mixing. We believe this demonstration experiment can be performed in most classrooms.

Nowadays, technologies involving nanoparticles, colloids, sensors, and artificial intelligence are widespread in society, media, and industry. It is thus mandatory to integrate them into the curricula of students enrolled in chemistry and materials science. To this purpose, we designed a simple assay for the detection of glutathione (GSH) using…

It's not surprising that rainbows have received a great deal of attention: in textbooks, in magazines, and on the web. They are, after all, beautiful, fascinating, occasionally awe-inspiring, even a little mysterious. They are an almost perfect blend of natural beauty and simple physics. Has everything that can be said about rainbows already been…

In this article, a consecutive series of four hands-on experiments are recommended to teach the colors of paint/pigment and their mixtures. These activities, which are effective in learning about how to make a simple observation and help to build argument-based knowledge about colors, offer an integrated and innovative way of teaching colors of…

Water can exhibit many different colors due to a variety of physical properties. Here, we focus on some observable colors within very pure freshwater. We only treat the absorption of light due to electronic and ro-vibrational excitations and scattering due to refractive index fluctuations of the water and the respective consequences for the…