Particulate Nature of Matter
NoteWhat This Chapter Covers
Break a piece of chalk again and again — how small can it get? Stir sugar into water and it vanishes — where does it go? This chapter answers with one big idea: all matter is made of tiny particles, far too small to see, with empty spaces between them and attractions holding them together. The strength of those attractions, set by the particles’ heat energy, is what makes something a solid, a liquid or a gas. We’ll watch particles vibrate, flow, escape and spread — and explain everything from melting ice and a clinging smell to why sugar dissolves but sand does not.
Learning Outcomes
By the end of this chapter, you will be able to:
- explain that matter is made of constituent particles with interparticle spaces and interparticle attractions;
- compare solids, liquids and gases in terms of shape, volume, spacing, attraction and particle movement;
- define melting point and boiling point, and explain melting, boiling and evaporation;
- explain why gases are compressible but liquids and solids are practically not;
- describe diffusion (spreading of particles) and how it speeds up with temperature.