Colorful transitions of various acid-base indicators have been used to illustrate the concept of chemical equilibria, especially in spectrophotometric determination of the equilibrium constants or pKa values. To accommodate an online laboratory environment necessitated by the COVID-19 pandemic, this work employs color analyses from digital images…

In the laboratory experiment described here, students synthesize silver nanostructures (AgNS) with different shapes and sizes to elucidate the shape- and size-dependent optical properties of nanostructured materials. Students also develop understanding of some thermodynamic and kinetic aspects of the synthesis process through this experiment. In…

The Australian Curriculum: Science for Year 5 includes "recognising that the colour of an object depends on the properties of the object and the color of the light source". This article shows how much more can be done with color in the science laboratory. Activities include using a prism to explore white light, using a hand lens to…

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…

The use of the Beer-Lambert law in spectroscopy is the core of standard methods for determining a chromophore concentration in a solution. Its application requires an understanding about interaction of light with a colored solution and the use of light emission and light detection devices. We build here a simple electronic circuit formed of…

Is moonlight "silver" or "cold"? In this paper we discuss the interesting combination of factors that contribute to the common descriptions of moonlight. Sunlight is reflected from the lunar surface and red-shifted. When traversing the atmosphere, moonlight is further depleted of short wavelength content by Rayleigh scattering.…

In the last decade, our understanding of the chemistry of olive oil has dramatically improved. Here, the essential chemistry of olive oil and its important minor constituents is described and related to the typical sensory categories used to rate and experience oils: color, aroma, bitterness, and pungency. We also describe experiments to explore…

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…

In this article, we present an overview of a suite of light and spectroscopy education materials developed as part of Project LITE (Light Inquiry Through Experiments). We also present an analysis of how introductory college astronomy students using these Project LITE materials performed on the Light and Spectroscopy Concept Inventory (LSCI)…

Explains the physical principles which result in various colors of the sky. Topics addressed include: blueness, mystical properties of water vapor, ozone, fluctuation theory of scattering, variation of purity and brightness, and red sunsets and sunrises. (DH)

Instructions accompanied by illustrations for building a low-cost demonstration spectroscope are presented. Materials and tools are pictured and labeled. Cost is estimated at five dollars (in 1980) and twelve hours of work are required to build the spectroscope. (SA)

Examines the physical basis for colors of noble metals (copper, silver, gold) developed from energy conservation/quantum mechanical view of free electron photoabsorption. Describes production of absorption edges produced by change in density of occupied valence electron states in the d-band, which allows stronger absorption in the visible photon…

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…

Describes an apparatus (called the "Rainbow Cup") used for demonstrating the colored rings produced by constructive interference in soap films. Discusses construction of the Rainbow Cup and gives hints for its use in the classroom, especially in relation to classroom humidity. (JM)