Common wisdom holds that ATP hydrolysis is spontaneous because of the weakness of its phosphoanhydride bonds, electrostatic repulsion within the polyanionic ATP[superscript 4]-molecule, and resonance stabilization of the inorganic phosphate and ADP products. By examining the pH-dependence of the hydrolysis Gibbs free energy, we show that in fact,…

The Young-Laplace (Y-L) equation relates the pressure difference across the interface of two fluids (such as air and water) to the curvature of the interface. The pressure rises on crossing a convex interface such as a rain drop and falls on crossing a concave interface such as the meniscus of water in a glass capillary. The relation between…

General Chemistry serves virtually all STEM students. It has been accused of covering content in a "mile wide and inch deep" fashion. This has made it very difficult to assess, where chemistry educators have relied on assessments of specific topics. Assessing across all these different topics requires introducing many different chemical…

Recent science education reforms, as described in the "Framework for K-12 Science Education" (NRC, 2012), call for three-dimensional learning that engages students in scientific practices and the use of scientific lenses to learn science content. However, relatively little research at any grade level has focused on how students develop…

When the thermal expansion of water is discussed in school or university lessons, functional relationships are often inferred without considering measurement uncertainties. Moreover, in some learning materials, the goal of experimentation and the experimental setup do not match. This creates the wrong picture of scientific practice. In this…

In his interesting and informative book "Is That a Fact?," Joe Schwarcz avers that pigs do not sweat and the saying "sweating like a pig" originates in iron smelting. Oblong pieces of hot iron, with a fancied resemblance to a sow with piglets, cool in sand to the dew point of the surrounding air, and hence water condenses on…

Developing scientific literacy about water systems is critical for K-12 students. However, even with opportunities to build knowledge about the hydrosphere in elementary classrooms, early learners may struggle to understand the water cycle (Forbes et al., [Forbes, C. T., 2015]; Gunckel et al., [Gunckel, K. L., 2012]; Zangori et al., [Forbes, C.…

As students increasingly use online chemistry animations and simulations, it is becoming more important to understand how students independently engage with such materials and to develop a set of best practices for students' use of these resources outside of the classroom. Most of the literature examining students' use of animations and…

We analyse why it is erroneous to think that a tidal bulge is formed by pulling the water surface directly up by a local vertical tidal force. In fact, ocean tides are caused by the global effect of the horizontal components of the tidal forces.

In this article we examine cases of more classical and less classical nature compared to results found by quantum mechanics and attribute a form of Free Energy discontinuity for each case within a boundary layer. The concept of a boundary layer is broadened as to include areas of first or second variations of the Gibbs free energy. It is…

In this article we discuss the concept of equilibrium establishment in four most usual instances as is electrostriction and vaporization as related to the concept of equilibrium shell formation. Two more cases are then studied which are of relevance. One is the Brownian movement, the study of which is essential for pedagogical reasons as to…

While ice is usually referred to as ice cubes, indeed, most are not really cubes at all. In this 5E learning-cycle lesson, students will investigate different shapes of ice and how shape affects the speed of melting and the rate of cooling a glass of water. Students will compare three different shapes of ice with the same volume but different…

The present research aims at pinpointing differences in spontaneous and non-spontaneous mental models of water cycle conceptions of two 4th grade student groups: the Jewish residents of a small provincial town and a group of students from an indigenous Bedouin community. Students' conceptions were elicited using the Repertory Grid technique as…

How "green" are 15-year-olds? To what extent do they understand environmental issues? What are the sources of their information about the environment? Can they apply scientific principles and evidence to the world around them? This paper reports that across OECD (Organisation for Economic Cooperation and Development) countries, around…

This column focuses on promoting learning through assessment. The author discusses the formative assessment probe "Pond Water," which reveals how elementary children will often apply what they know about animal structures to newly discovered microscopic organisms, connecting their knowledge of the familiar to the unfamiliar through…