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…

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…

This article argues that we need to make use of our everyday experiences when introducing concepts in chemistry that are often obscure. It uses reaction rates as an example and explores a common misconception related to the explanation of the effect of rising temperature on the rate of slow reactions.

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…

Undergraduate and graduate students' predictions and submicroscopic level explanations for the melting of four materials (salt, chalk, sugar, and butter), and for the mixing of these solutes in two solvents (water and cooking oil) were collected. Twenty-three undergraduate students and seven graduate students participated in the study, and data…

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…