Although nearly everyone is familiar with colors from an early age and the fundamentals of color mixing are taught at various abstraction levels throughout kindergarten to high school, we repeatedly observe that our student teachers in physics have problems in explaining the subject. Therefore, we propose an experimental setup that focuses on the…

Teaching the periodic table is a central part of chemistry. This might involve memorizing the symbols of the elements, learning about the properties of the families, or understanding its general organization. This year, The International Year of the Periodic Table, marks its 150th anniversary, and represents a good opportunity to highlight its…

Candy, an everyday treat, is a convenient theme for teaching chemistry. Making candy incorporates solution concentration, colligative properties, and phase transformations while flavoring and color reflect synthesis or extraction. In this article, a nonscience major laboratory course on candy chemistry is presented. The course combines laboratory…

Low cost, open-source analytical instrumentation has the potential to increase educational outcomes for students and enable large-scale citizen science projects. Many of these instruments rely on smartphones to collect the data, mainly because they can effectively leverage a dramatic price-to-performance ratio of the optical sensors. However,…

Flotation as a method of separation is widely researched and is applied in many industries. It has been used to address a wide range of environmental issues including treatment of wastewater, recovery of heavy metals for recycling, extraction of minerals in mining, and so forth. This laboratory attempts to show how such a simple method can be used…

In this article, we present two concrete applications of the concept of the human element to chemistry education; starting with a course and experimental project on blue pigment synthesis and concluding with cross-disciplinary lessons and experiments on blue photography. In addition to the description of the content of these courses, we explore…

In this article we propose an activity aimed at introductory students to help them understand the Stefan-Boltzmann and Wien's displacement laws. It only requires simple materials that are available at any school: an incandescent lamp, a variable dc energy supply, and a computer to run an interactive simulation of the blackbody spectrum.…

An update to the thermochromic cobalt(II) chloride equilibrium demonstration is described. Filter paper that has been saturated with aqueous cobalt(II) chloride is heated for seconds in a microwave oven, producing a color change. The resulting pink and blue map is used to colorfully demonstrate Le Châtelier's principle and to illuminate the hot…

By attaching LEDs and lasers to moving objects, and shining their light on photochromic surfaces below them, we can display traces of many motions of interest in introductory physics courses and science museums.

Teaching prismatic colours usually boils down to establishing the take-home message that white light consists of "differently refrangible" coloured rays. This approach explains the classical spectrum of seven colours but has its limitations, e.g. in discussing spectra from setups with higher resolution or in understanding the well…

FriXion erasable pens contain thermochromic inks that have colored low-temperature forms and colorless high-temperature forms. Liquid nitrogen can be used to kinetically trap the high-temperature forms of the ink at temperatures at which ordinarily the low-temperature forms are more thermodynamically stable. (Contains 2 figures.)

The synthesis and characterization of two copper(II) complexes, [Cu(deen)[subscript 2]](BF4)[subscript 2] and [Cu(deen)[subscript 2]](NO[subscript 3])[subscript 2] (deen = N,N-diethylethylenediamine), that show interesting thermochromic properties, are described. The subtle alternation of coordination geometry around Cu(II) is responsible for the…

A sticky capture thread from the spiral element of spider orb-webs is formed of almost regularly spaced droplets that surround a supporting axial fibre. From the perspective of physical optics it represents a periodic linear array of scattering elements that acts as a diffraction grating. This is a novel aspect, which is of vital importance for…

When viewing objects of different colors, you might notice that some appear brighter than others. This is because light is reflected differently from various surfaces, depending on their physical properties. The word "albedo" is used to describe how reflective a surface is. The Earth-atmosphere has a combined albedo of about 30%, a number that is…

This article examines several readily available "magic tricks" which base their "trickery" on physics principles, and questions the use of the word "magic" in the 21st century, both in popular children's science and in everyday language. (Contains 18 figures.)