The importance of teaching the Luria-Delbrück experiment to biology students is increasingly recognized by educators, and improved pedagogical methods for teaching the classic experiment have been proposed and tested in the classroom. However, there are still obstacles that impede the proper teaching of the classic experiment. This note proposes…

Oblique angle collisions of two penny coins on a smooth, horizontal surface were filmed with a video camera to investigate the physics of the collision process. If one of the coins is initially at rest, then the two coins emerge approximately at right angles, as commonly observed in billiard ball collisions and in puck collisions on an air table.…

The refractive index (RI) is probably the single most important parameter in optical systems. Chromatic dispersion, on the other hand, indicates how the RI depends on the wavelength and is central in, e.g., optical communication systems. Chromatic dispersion also plays an important role when teaching optics due to the captivating natural…

The double-indicator method is often used in the analysis of Na[subscript 2]CO[subscript 3], NaHCO[subscript 3], and NaOH mixtures (carbonate mixtures). In this method, the determination of the volumes at the first and second equivalence points plays a crucial role in analyzing the composition and content of the carbonate mixtures. Here, LabVIEW…

An activity is described that uses simple materials and an easy-to-perform protocol to estimate the Curie temperature of nickel, which is the temperature at which nickel loses its ferromagnetism. To do so, an object made of nickel metal is heated with a lighter until it loses its ferromagnetism. The metal is allowed to drop into a beaker that…

The construction and characterization of a glucose biosensor has been implemented in an instrumental chemical analysis course to provide students experience with chemical sensing, electroanalytical methods, and flow injection analysis (FIA). The glucose biosensor was assembled on a glassy carbon electrode by depositing a layer of Prussian blue…

In chemistry, a eutectic mixture refers to a mixture of two or more components at which the lowest possible freezing point is observed. This phenomenon is covered in a wide range of curricula such as physics, chemistry, chemical engineering, and pharmacy to various depths. Despite the significance of this phenomenon in pharmaceutical compounding…

This article describes an enrichment and extension of a published applied chemistry experiment involving the use of distilled fragrant compounds of natural plants to prepare facial toner. The original protocol failed to consider quality evaluation of the self-prepared facial toner. Herein, an additional experimental section is included for…

The Crookes radiometer (also known as a light mill) is a fascinating sunlight-powered device, in which a set of vanes is placed inside a glass bulb within which a partial vacuum has been pulled. The vanes then rotate when sunlight shines on the bulb. The reason for the turning of the vanes was subject to intense debate and many students still have…

This paper outlines a comprehensive teaching laboratory course program that centers on titration analysis, a timeless and essential technique in analytical chemistry spanning various disciplines, such as environmental science, medicine, and industry. In these fields, titration analysis is paramount for determining the concentrations of substances…

Multistep synthesis is a key capstone experience in organic laboratory instruction. Here, a four-step synthesis of avobenzone, an active component in sunscreens, has been developed that can be completed in two 4 h laboratory periods. This synthesis incorporates green principles and includes an aldol condensation, electrophilic addition of bromine…

One step of the published mechanism of the hydrogen peroxide iodine-clock reaction is called into question by the result of an experimental attempt (predicated on that mechanism) to integrate that reaction into the elephant's toothpaste demonstration to reveal and control its iodine side product. Under conditions that were a hybrid of those…

In this paper we consider the well-known experiment with the 'heavy' newspaper that breaks a stick that it is laid on. Using several appropriate control experiments we show that the currently invoked explanation using atmospheric pressure cannot be correct. We perform a theoretical analysis and propose a new explanation based on the rotational…

This paper introduces a safe, interesting, convenient, and low-cost experiment. The products of galvanic cells and electrolytic cells are compressed into specimens that are placed on a slide to stretch the metal dendrites in one plane and ensure they are not easily destroyed by external factors. The details and growth process of the metal…

A previous journal article established that a hanging Slinky's restoring force is due only to the coils between the support and the Slinky's center of mass (hereafter COM). Correspondingly, it is expected the Slinky's elastic potential energy (hereafter EPE) is associated with only those coils; however, there is no confirming experimental…