Newton's laws are essential for understanding causes and description of mechanical motion. Great attention is paid to them during physics education. Unfortunately, many students, not only in high school, but also undergraduates, can recite them but do not understand their essence. Therefore, it is useful to demonstrate different experiments in the…

The five papers published by Hodgkin and Huxley in 1952 are seminal works in the field of physiology, earning their authors the Nobel Prize in 1963 and ushering in the era of membrane biophysics. The papers present a considerable challenge to the novice student, but this has been partly allayed by recent publications that have updated the…

The ideal gas law, "PV = nRT," is one of the simplest physical laws in nature that is introduced to students as early as in high school and first year in college. In this equation, "P" stands for pressure, "V" is the volume, "n" is the amount expressed in mole, "T" is the temperature in Kelvin…

In this article we present a simple technique for determination of the Young modulus of the material of a metallic ruler using it as a cantilever. This method employs with a slide potentiometer and a digital multimeter. The linear region of potentiometer resistance which is calibrated in terms of length has been used to record the load vs.…

The refractive index of a liquid is known to depend strongly on the temperature gradient of liquids. When a laser beam passes through a transparent material going through thermal diffusion, the light projected onto a screen will be displaced in relation to the thermal diffusivity. A simple apparatus is used to measure the time evolution t of the…

Granular flows appear frequently in the natural world and in civil engineering applications. These flows can exhibit features which are surprising and counter-intuitive and are often used to test the limits of the classical continuum approximation for modelling of fluid flows. An important sub-class of the granular flows are the gravity-driven…

Teaching the noncommutativity of the product of matrices to high school or college level students is a difficult task when approached from a purely formal perspective. The aim of this paper is to present a simple experimental activity for teaching the noncommutativity of the matrix product, based on the Jones calculus, a mathematical formalism for…

We present an experiment designed to study standing waves in a tube with one closed end. Two smartphones are used, one to emit a sound signal with a chosen frequency and another equipped with a microphone to detect the sound pressure level inside the tube. Due to the finite diameter of the tube, the standing wave node (or antinode) appears…

[This paper is part of the Focused Collection on Instructional labs: Improving traditions and new directions.] In this paper, we describe the results of a research project whose goals were to (1) develop and implement video-based experimental investigations using the Investigative Science Learning Environment (ISLE) approach and (2) study how…

This report describes a laboratory experiment for an undergraduate-level inorganic chemistry or biochemistry course involving the study of the kinetics of the catecholase activity of a synthetic nickel­(II)-oximate complex. A model substrate, 3,5-di-tert-butylcatechol(DBC), undergoes aerobic oxidation to 3,5-di-tert-butylbenzoquinone (DBQ) in the…

Poinsettia ("Euphorbia pulcherrima") contains anthocyanins that dissolve in water and exhibit color changes due to changing pH. This property makes the poinsettia extract a useful acid-base indicator for pH demonstrations. When combined with common household materials, this experiment can be used as an alternative low-cost tool in…

MóviLab (Moving Lab) was an educational strategy developed at Universidad Industrial de Santander, Colombia, to promote chemistry and science among schoolchildren and teenagers from far rural areas of the Santurbán moor in Colombia during the COVID-19 pandemic. The strategy consisted of designing a kit with chemistry experiments that could be done…

Herein, two simulated electrochemistry experiments, namely, the (i) electrochemical series, using an electronic half-cell module, and (ii) citrus fruit battery series are demonstrated for undergraduate chemistry students. The demonstration can be performed for in-person and remote students by connecting the electronic half-cell module to a…

The essential component of expanding an undergraduate curriculum is the inclusion of lab experiments in nanoscience and nanomaterials, which significantly impact health and the environment through their use in food, cosmetics, agriculture, and medicine. We designed a laboratory experiment based on the atomic force microscopy (AFM) analysis of the…

Electrochemistry plays a crucial role in our everyday lives. It allows us to power our phones and cars and allows for the real-time monitoring of blood glucose levels. While electrochemistry is of vital importance and is a long-established field of chemistry, it is often neglected in modern curricula for STEM courses. Herein, we show that hands-on…