The question from the title is raised because in almost all introductory physics courses/textbooks the atmospheric pressure has been attributed to the weight of the column of air from a given level in the atmosphere up to its top. "Air is pressing on air." However the same textbooks, in the chapter on the kinetic theory of gases, tell…

The distinction between pressure in a liquid and in a gas is often treated in a cursory way, or not treated at all, even in university level textbooks. Most texts fail to point out the relation between pressure and density in a gas as compared to pressure in a--virtually incompressible--liquid. In many instances this also results in a dismissive…

The cannon boring experiment of Count Rumford, where eight kilograms of water were boiled by metal on metal friction, is investigated. Consideration of this dramatic demonstration can enrich classroom discussions of calorimetry, units of measure, elements, and thermodynamics. A section pertaining to use of the article in the classroom appears…

This paper seeks to evaluate learning based on the competency approach, taking a didactic experience to evaluate a possible improvement in the ability to solve problems and for autonomous learning in general. For the didactic development, the theme "gases" was taken, which is generally enunciated: Corpuscular kinetic theory of matter;…

Thomas Graham discovered the law that bears his name while studying gas diffusion into air and other gases. He also found that the same relationship held with gas effusion, the movement of gases through a pinhole into a vacuum. Modern understanding of diffusion and effusion is based on kinetic-molecular theory, and it is generally accepted that…

We present an interactive discovery-based approach to studying the properties of real gases using simple, yet realistic, molecular dynamics software. Use of this approach opens up a variety of opportunities for students to interact with the behaviors and underlying theories of real gases. Students can visualize gas behavior under a variety of…

Context-based learning (CBL) is advocated as beneficial to learners, but more needs to be understood about how different contexts used in courses influence student outcomes. Gilbert defined several models of context that appear to be used in chemistry. In one model that achieves many criteria of student meaning-making, the context is provided by…