In this research, an educational approach to the concept of energy is proposed. It is based on the history of physics. In 1854 Hermann Hemlholtz gave a popular lecture on the recent discovery that energy is conserved. Such lecture is used as a guide to introduce the pupils within several nuances of this concept. Not much mathematics is used, so…

Of all the conceivable ideal-gas processes, almost all introductory physics textbooks as well as more advanced texts on thermodynamics emphasize only four: isochoric, isobaric, isothermal, and adiabatic (isentropic). These are processes in which a state variable--volume, pressure, temperature, or entropy--remains constant. It turns out that these…

Using the analogy between thermodynamics and electricity, two new concepts of thermal charge and quantity of thermal charge are introduced. A simple yet explicit definition of entropy is then derived-entropy is the quantity of thermal charge. As a result, quantity of thermal charge (entropy) and quantity of heat (energy) are now clearly…

Why do we need to pour less water in an egg steamer to prepare more eggs to the same degree of 'doneness'? We discuss the physical processes at work in the electric egg steamer and resolve this seeming paradox. We demonstrate that the main heat transfer mechanism from steam to egg is due to latent heat through condensation. This not only explains…

With the rapid spread of high-speed railway technology, there is a resurgence of interest in trains and railways. The main propulsive engine for railways was the steam engine for over a century, which gave way to the diesel and electrical engines. The steam engine was crucial to the birth and development of the railway industry, and understanding…

In this paper a well-known experiment is considered that is used to demonstrate some aspects of water boiling. It is shown that the currently popular explanation is wrong and a better explanation is proposed, backed up with experimental data. Variations of the experiment are proposed that can be used for a more in-depth examination of the…

The anomalous thermal expansion of water in the 0 °C-4 °C range is extremely important to life on Earth, but it is normally not presented experimentally in educational settings. This paper presents a simple experiment to explore the anomalous thermal expansion of water in the 0 °C-4 °C range and the heat exchange processes in natural bodies of…

The design and operation of the vapor-absorption refrigerator (VAR) are described using the principles and tools typically covered in upper-division undergraduate physical chemistry courses. The objective is to enable students to understand in detail how this device works and how it compares with more typical vapor-compression refrigerators.…

Students have several misconceptions about thermodynamics. However, an understanding of basic concepts in this branch of physics remains fundamental to explain thermal phenomena. The purpose of this activity was to extend students' conceptual understanding of heat, temperature, energy, and thermal insulators and conductors. Two groups of students…

Watching over a coffee maker in operation, and designing a simple experiment using it, invokes familiar and unfamiliar physical phenomena and techniques involving calorimetry and heat transfer.

Constructing causal mechanistic explanations of observable phenomena is a key science practice that is often challenging for students as most mechanisms involve interactions of unobservable entities and activities. In this study, we examined how gesturing with a computer simulation that depicts the molecular mechanism of thermal conduction…

Sixth-grade science students at Gauger-Cobbs Middle School in Newark, DE, had misconceptions about how heat energy moves in the hydrosphere through conduction, convection, and radiation. As a result, students struggled to develop and connect ideas that correctly and completely explained heat transfer in the hydrosphere at the end of the lesson…

The achievement of a proper conceptual change is a challenge for students since there are some constraint-based interactions including different ontological categories with the well-known dichotomy of matter or process. To mitigate this state of affairs, more instructional sequences with pedagogical approaches are needed because many students,…

Physical and virtual labs have unique capabilities that can influence how students learn from them. The purpose of this study was to examine the effect of physical and virtual manipulatives on students' learning of heat and temperature and to examine the influence of various combinations of physical and virtual manipulatives. A total of 205…

A spreadsheet-based exercise for students is described in which they are challenged to explain and reproduce the disparate temperature dependencies of the heat capacities of gaseous F[subscript 2] and N[subscript 2]. For F[subscript 2], C[subscript p,m] increases from 300 K, reaches a maximum at 2200 K, and then decreases to 74% of the maximum…