The effect of surfactant adsorption on surface tension, as well as associated thermodynamic concepts are introduced in a laboratory experiment designed for undergraduate students. Using a reliable and accessible method, students measure the surface tension of aqueous solutions at different concentrations of sodium dodecyl sulfate. Students collect…

We have developed a laboratory project in which students prepare liposomes, expose them to hyperosmotic and hypoosmotic solutions, and follow the resulting shrinking and swelling (respectively) with laser light scattering. Each light intensity transient can be fit to an exponential decline or rise, with the decay constant (k) and the amplitude…

In tabletop games involving dice, it is important to ensure randomness of the dice rolls and to protect other gaming elements from being scattered by rolling dice. One way of ensuring random rolls and protecting gaming elements is to drop dice into a dice-rolling tower ("dice tower"). A dice tower is usually small (20 cm by 20 cm) and…

The physical and chemical properties of Milk of Magnesia provide examples of chemical concepts and opportunities for investigative practical work for secondary chemistry students of all ages. Basing the lesson on the contents of that familiar blue bottle, which is probably lurking somewhere in a cupboard in most households, also showcases the role…

This high school-level, place-based, inquiry-driven laboratory module familiarises students with techniques used to analyse animal behaviour while facilitating the development of the observational skills highlighted by the Next Generation Science Standards (NGSS). Throughout the module, students observe, quantify, and discuss local invertebrate…

Affective and cognitive outcomes of science teaching in schools may be enhanced by science outreach labs (SOLs). Particularly interesting is whether and how to connect SOL visits to in-school science learning. Recent studies--among others, in this journal--have confirmed SOLs' positive affective effects. However, research remains inconclusive…

In 2017, almost everywhere in the world, there was a boom in sales of fidget spinners. A toy that has 'multi-lobes' that can rotate freely from a thrust performed with the fingers. Thereby, we analysed the physics concepts that involved in this toy, such as angular and linear velocity. We did the analysis using the software Tracker, a laboratory…

We commonly ask students to compare the results of their experimental measurements with the predictions of a simple physical model that is well understood. However, in practice, physicists must compare their experimental measurements with the predictions of several models, none of which may work well over the entire range of measurements. The…

A novel method of measuring the coefficients of kinetic and rolling friction is proposed. The method is simple to implement and reliable. Samples of measurements and calculations are presented.

Gas-phase nitrogen oxides are important in the formation of tropospheric ozone. NO[subscript x] (NO and NO[subscript 2]) as well as tropospheric ozone have been shown to have negative effects on human health. Therefore, accurately measuring NO[subscript x] concentrations in the atmosphere is important. In this laboratory experience, students…

While it has been demonstrated how air resistance could be analyzed by using mobile devices, this paper demonstrates a method of how to determine the drag resistance coefficient "c" of a commercial automobile by using the acceleration sensor of a smartphone or tablet. In an academic context, the drag resistance is often mentioned, but…

This work describes a simple experiment to measure the resistor temperature as a function of the applied power and proves that it is an efficient way to introduce some important physical concepts in classroom, including the Joule's first law, hot-spot temperature, thermal resistance, thermal dissipation constant, time constant and the Newton's law…

The separation of chamazulene from hydrophilic contaminants present in blue tansy oil provides a visually engaging example of two common techniques: extraction and thin-layer chromatography (TLC). This application uses liquid CO[subscript 2] as a lipophilic solvent to pull a brilliant blue hydrocarbon molecule, chamazulene, out of or through a…

This laboratory experiment leverages the pedagogical value and multidisciplinary nature of biodiesel production from vegetable oil to introduce students to continuous-flow chemistry, a modern and rapidly growing approach to chemical synthesis. An interdisciplinary approach exposes students to the practical and conceptual aspects of modern…

Expensive, highly reflective barium sulfate plates are typically used to obtain solid-state UV-vis electronic spectra. Through normal laboratory use these plates become dirty, chip, and break, thus requiring replacement. An alternative to purchasing new plates is to make your own by combining a mechanical stabilizer, such as gum arabic, with…