Despite having previously examined a phase-change diagram in detail (here) I haven't yet covered the particle model and how it links to different states of matter. So that topic, which is relevant for both chemistry and physics, is the focus of this article. First let's clarify the terminology... we will be confining ourselves to the … Continue reading Changes of State
Kinetic Theory
Scientific theories are constructs (models) that we use to explain our observations. They are different from scientific laws, which are rules that have to be obeyed and which can be applied across a wide variety of situations. The best known example is the Big Bang Theory but we'll be looking at a theory that relates … Continue reading Kinetic Theory
Thawing a frozen balloon
The pressure, volume and temperature of a gas are all linked so it makes sense to keep one of them constant when investigating the interdependence of the other two. But we didn't do that when we watched the effect of liquid nitrogen on a partially-inflated balloon - as shown in the animation below. Before viewing … Continue reading Thawing a frozen balloon
Absolute Zero
Where does the idea of "absolute zero" come from? In part it stems from a need to avoid negative temperatures but a better explanation can be found by thinking about the kinetic theory of gases. When a gas is heated, its particles gain kinetic energy. This in turn means that the particles have a higher … Continue reading Absolute Zero
