A laboratory activity is described for senior high school or first year undergraduate level students that illustrates key concepts linked to extractive metallurgy. This experiment demonstrates preferential binding of a methoxyphenolic oxime ligand to Cu[superscript 2+] in the presence of other transition metal ions in aqueous solution. The…

Most didactic lab experiments deal with the influence of temperature, concentration, pressure, surface area, and catalysts on chemical kinetics; however, few of them explore the influence of light radiation and the presence of inhibitor agents on reaction rates. In order to investigate the effects of the radiation source and the presence of…

As soon as children can see, they observe that objects fall freely. From a young age, we spontaneously construct interpretative models to understand this everyday phenomenon. Over the last three decades, numerous experiments have been developed to help students understand physics concepts regarding free fall. Although there are many…

Technically simple and extremely cheap setups for colorimetric and fluorimetric analyses using a smartphone camera are presented. Laboratory activities on digital colorimetric and fluorimetric analyses for students of secondary and higher educational institutions are proposed, namely, photocolorimetric determination of acetylsalicylic acid in…

Polychlorinated biphenyls (PCBs) are a family of synthetic chemicals consisting of carbon, hydrogen, and chlorine atoms. PCBs have been produced commercially since 1929 in hundreds of industrial applications. Their continued production in the United States was phased out in the late 1970s, and strict disposal guidelines were regulated as adverse…

As e-commerce increases, the demand for packaging materials and the potential for generating waste and negative environmental impacts also rise. Packing peanuts are a type of plastic packaging material that are used to protect goods during the shipping process. Petroleum-based plastics are common packaging materials due to their low cost, light…

We discuss the use of a simple piece of equipment made of a 50 mL syringe attached to a 2 mL graduated pipet to demonstrate Boyle's law and Charles's law. A plot of the hydrostatic pressure against the reciprocal of the volume of the gas read from the equipment is linear as discussed in the paper and gives the atmospheric pressure at the…

Understanding thermal concepts constitutes one of the most important challenges in teaching science as these concepts are central to the principals of science and allow students to build connections among scientific disciplines. From an early age, students' interaction with daily phenomena and real situations comes to shape their conceptions of…

The vertical bounce of a plastic egg was investigated by dropping the egg on a horizontal surface and filming the result with a video camera. If the egg is dropped on one end then it bounces just like a spherical ball. If the top end of the egg is pointing forwards or backwards when it lands on the surface, or if the egg is spinning when it lands,…

Digestion is a fundamentally important process for an individual's life. However, the physical process of digestion is hidden inside the body, making it challenging to understand and a particularly difficult topic for students to learn in the classroom. Traditional approaches to teaching body processes include a mixture of textbook teaching and…

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…

The fact that a bungee jumper can reach an acceleration greater than the acceleration of gravity is, also from a physics point of view, intriguing. Taking only gravity into account, it can be explained by applying conservation of energy or by deriving carefully the equation of motion in a Newtonian approach. In this article we show how it can be…

In classroom science laboratories, unlike a real science laboratory, the teacher can guide students away from potential dead ends and toward data that are most likely to result in accurate conclusions. Sometimes, though, allowing students to pursue dead ends and to collect "bad" data can provide especially rich learning opportunities.…

Thin-layer chromatography (TLC) is one of the basic analytical procedures in chemistry and allows the demonstration of various chemical principles in an educational setting. An often-overlooked aspect of TLC is the capability to quantify isolated target compounds in an unknown sample. Here, we present a suitable route to implement quantitative…

We present a sequence of two physics experiments, designed for use with secondary students, which investigate the specific heat of sand, both qualitatively and quantitatively, without a calorimeter. We use two LM35 temperature sensors and an Arduino prototype board for data acquisition. The results are good and allow teachers to discuss the…