In 1827, Robert Brown noticed pollen suspended in water bouncing around erratically. It wasn't until 1905 that Albert Einstein provided an acceptable explanation of the phenomenon (Kac 1947): Brownian motion is the random movement of particles (e.g., pollen) in a fluid (liquid or gas) as a result of collisions with atoms and molecules. Movement of…

In the present theoretical study, we introduce the entropy concept into Chi's ontological shift theory. Chi distinguishes between two categories of process phenomena, direct and emergent, and claims that incorrectly considering emergent processes as direct ones is one of the sources of students' robust scientific misconceptions. The present study…

An experiment is described that determines the activation energy (E[subscript a]) of the iodide-catalyzed decomposition reaction of hydrogen peroxide in a much more efficient manner than previously reported in the literature. Hydrogen peroxide, spontaneously or with a catalyst, decomposes to oxygen and water. Because the decomposition reaction is…

This article describes engaging students in two simple observations to address the concepts of changes of states, heat, temperature, and molecular potential and kinetic energy. It also discusses how these concepts can enable students to further explore and understand interesting and significant phenomena and research in multiple areas of science.…

Evaporation and boiling are both terms applied to the change of a liquid to the vapour/gaseous state. This article argues that it is the formation of bubbles of vapour within the liquid that most clearly differentiates boiling from evaporation although only a minority of chemistry textbooks seems to mention bubble formation in this context. The…

The physics and chemistry education literature has grappled with an appropriate definition for the concept of heat for the past four decades. Most of the literature promotes the view that heat is "energy in transit" or "involves the transfer of energy" between the system and surroundings because of a difference in temperature. Given that many…

This experiment and analysis offer an economic yet challenging semi-batch reactor experience. Household bleach is pumped at a controlled rate into a batch reactor containing pharmaceutical hydrogen peroxide solution. Batch temperature, product molecular oxygen, and the overall change in solution conductivity are metered. The reactor simulation…

Over the last few decades, smart materials have become increasingly important in the design of products. Essentially, a smart material is one that has been designed to respond to a stimulus, such as a change in temperature or magnetic field, in a particular and useful way. This article looks at a range of smart materials that are relatively…

The literature has revealed that many students encounter substantial difficulties in applying the first law of thermodynamics. For example, university students sometimes fail to recognize that heat and work are independent means of energy transfer. When discussing adiabatic processes for an ideal gas, few students can correctly refer to the…

Understanding the particulate nature of matter (PNM) is vital for participating in many areas of science. We assessed 11 students' atomic/molecular-level explanations of real-world phenomena after their participation in a modelling-based PNM unit. All 11 students offered a scientifically acceptable model regarding atomic/molecular behaviour in…

A model of a thermodynamic system is described in which particles (representing atoms) interact with one another, the surroundings, and the earth's gravitational field according to the principles of classical mechanics. The system's energy "E" and internal energy "U" are defined. The importance is emphasized of the dependence of energy and work on…