A simple demonstration adaptable to classroom conditions is presented, which involves the preparation of raffle tickets using filter paper and the solution of selected fluorophores. With an appropriate dilution, the text written on the tickets is not visible to the naked eye; however, it becomes readable once put under a UV lamp. Besides being a…

Student feedback from an undergraduate biochemistry lab course suggested the use of visibly traceable proteins may assist learning. Based on this feedback, we used guided inquiry lab exercises where students developed and characterized a suite of fluorescent protein-dihydrofolate reductase (DHFR) fusions as tools for a biochemistry teaching lab.…

Ever since Newton's groundbreaking work on the composed nature of light, additive colour mixing (and its laws) are subject to the interest of physicists as well as other sciences. In this paper, we present a setup for simple lab or home experiments on additive colour mixing and the laws of colour mixing. Students use the screen of a laptop or…

This paper demonstrates the use of a smartphone as a low-cost multi-channel optical fibre spectrophotometer suitable for physics laboratory classes. A custom-designed cradle and structure support were fabricated using 3D printing. The plastic optical fibres were arranged and inserted into the hole of the cradle to guide the light to the rear…

Gas emission tubes are widely used laboratory and demonstration apparatus because the line source nature of the tube produces line spectra when viewed directly through a diffraction grating. These are long and distinctly visible images of the tube, located to either side of the zeroth order at an angle determined by the wavelength. A continuous…

Laboratory experiments provide students a tangible means of understanding dry, abstract concepts. A simple and engaging introductory wet chemistry laboratory has been developed relating quantum mechanics to color, which has been implemented for a class of about 600 students per academic year for over three years at Brown University. Color is an…

One of the most mystifying products on the market for people at any age is the glow stick: a plastic tube that, when snapped, creates a flood of bright, brilliantly colored light without the use of electricity or significant production of heat. In this case, the chemiluminescence reaction also provides an exciting phenomenon through which we can…

A simple photometric assembly based in an LED as a light source and a photodiode as a detector is proposed in order to follow the absorbance changes as a function of the titrant volume added during the course of acid-base titrations in the presence of a suitable visual indicator. The simplicity and low cost of the electronic device allow the…

This study aimed to investigate the effect of experimenting with physical manipulatives (PM), virtual manipulatives (VM), and a blended combination of PM and VM on undergraduate students' understanding of concepts in the domain of "Light and Color." A pre-post comparison study design was used for the purposes of this study that involved 70…

To overcome students' inaccurate prior knowledge on primary additive colours, a coloured-light mixer has been constructed to enable students to observe directly the colours produced and reach the conclusion by themselves that the three primary colours of light are red, green, and blue (NOT red, yellow, and blue). Three closely packed tiny…

A new type of DVD spectroscope, the periscope type, is described and the numerical analysis of the observed emission and absorption spectra is demonstrated. A small and thin mirror is put inside and an eighth part of a DVD is used as a grating. Using this improved DVD spectroscope, one can observe and photograph visible spectra more easily and…

Traces the development of instruments used in spectrophotometry. Discusses how spectrophotometric measurements are made. Describes the color comparator, the filter photometer, and the spectrophotometer. Outlines the evolution of optical systems, including light sources, the monochromator, the photodetector, double-beam optics, and split-beam…