We have developed a guided-inquiry laboratory exercise in which students perform viscosity measurements to infer the structure of poly(vinyl alcohol) (PVA) in aqueous solution. The activity combines both experiments and modeling. In the experimental portion of the exercise, students measure the viscosity of several solutions of PVA with differing…

The article describes a methodology for studying Fresnel diffraction with the active involvement of students in discussing the results of a demonstration experiment. To create a clearly visible model of Fresnel zones, a centimeter radio wave range was chosen, in which the first zone is about 10 cm in size. This makes visible the created…

The principles of process-oriented guided inquiry learning (POGIL) are applied to the analysis of the emission spectrum of atomic hydrogen. Over the course of three learning cycles, students construct the hydrogen atom's energy level diagram and assign quantum numbers using their measurements of the Balmer series plus additional information on the…

We describe here a low-cost experiment for introductory physics students where they compare the physical properties of aluminum and steel by means of cantilever oscillations. This, in turn, allows the students to improve their physical intuition about these materials. Further, the students can apply their physics and mathematics knowledge and…

Due to immense cost reduction and routine commercial availability, 3D printing has become the cutting-edge technology with enormous potential--also for educational and applied chemistry. It opens the opportunity to print custom-made reactors, such as (micro) flow reactors. In addition, 3D-printing technology can simplify chemical reactions, such…

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…

In this article, we propose a simple and accessible model of a magnetic levitator fitted with a Hall sensor. This model also allows to determine the magnitude of the magnetic field within the levitator working volume. Students can also compare the experimental magnetic field values to reference values in magnetism textbooks. This Arduino-based…

The objective of this work was the theoretical modeling of a construct based on teaching practice about the perception that pupils have of difficulties in problem solving (PS) in experimental sciences, specifically physics, to predict pupil performance in PS. The research was carried out with an incidental sample of second year of secondary…

Genetics is known to be one of the most challenging subjects in biology education because of its abstract concepts and processes. Therefore, hands-on experiments in authentic learning environments are supposed to increase comprehensibility and provide otherwise unavailable experiences to students. We applied a hands-on module in an out-of-school…

A quantitative experiment where we measure the acceleration of spheres of radius "R" rolling on an inclined U-shaped profile of width "2D" is presented. For a given inclination, we examine the behaviour of four solid spheres having different diameters; in contrast to what is usually assumed to be the case, the experimental…

Most undergraduate students do not have practical experience working with model organisms despite having theoretical knowledge of their importance. This practical was developed to offer students experience working with three species of nematode, including "Caenorhabditis elegans." In the first task, students prepare slides of three…

A glass of water covered with a disk with a hole in it can be turned upside down without spilling the water in the glass, provided the hole is small enough and the disk is pressed against the rim of the glass. A quasistatic numerical simulation based on hydrostatic pressure and surface tension of water was used calculate the critical hole diameter…

In this paper, we present a physical modeling activity whose objective is to allow students to determine the differences between a disk and a sphere using pure scientific criteria. Thereunto, we reproduce the Sun-Earth-Moon system with low-cost materials and compare the illumination effects on the Moon considering two possible shapes for it (a…

It is common in science for two phenomena to appear to be very different, but in fact follow from the same basic principles. Here we consider such a case, the connection between the chain fountain and a bullet-block collision experiment. When an upward moving bullet strikes a wooden block resting on a horizontal table, the block will rise to a…

Most springs do not simply obey Hooke's law because they are constructed to have an initial tension, which must be overcome before normal elongation occurs. This property, well known to engineers, is universally neglected in elementary physics courses. In particular, the standard simple harmonic motion experiment omits any discussion of this…