Metals are polycrystalline; inside each crystal, atoms are regularly arranged and close together. Left alone, the atoms...

Teaching Guidance 14-16

The atoms or molecules in a gas are widely separated from one another and interact only when they collide. Each one changes...

Teaching Guidance 14-16

Theory, modelling, guessing and experimenting are all intertwined. Each step progressing from one idea to the next. However...

Teaching Guidance 14-16

Robert Brown is correctly referred to as having observed the jittering motion of small particles. But he did not observe the...

Teaching Guidance 14-16

Statistical studies, combined with the assumption that every molecular collision is elastic, lead to the conclusion that all...

Teaching Guidance 14-16

Imagine molecules in a gas; dots spaced far apart. Add arrows to show the random motion, not all speeds (arrows) the same but...

Teaching Guidance 14-16

The experimental graph of pressure against temperature is likely to be straight enough to justify asking whether the plotted...

Teaching Guidance 14-16

√N steps gives the average mean free path for a bromine molecule in its wandering amongst air molecules. That would be similar...

Teaching Guidance 14-16

Students will probably have met the simple molecular picture of solids, liquids and gases. Matter is, in every case, made up...

Teaching Guidance 14-16

It is interesting for students to see how far physicists can push ‘back of the envelope’ calculations. Diffusing bromine into...

Teaching Guidance 14-16

This proof of R = s√N describes an algebraic approach to the random walk problem, sometimes known as the drunkard’s walk: If...

Teaching Guidance 14-16

As a crude picture that will lead to a rough estimate, assume that each molecule in a liquid occupies a cubical box of side, d...

Teaching Guidance 14-16