Thermal Expansion

Syllabus tag: KCSE | Physics | Form 1 | Topic 6 Thermal Expansion

Lesson objectives

By the end of this topic, you should be able to:

• Explain expansion of solids, liquids and gases using the kinetic theory.
• Describe experiments demonstrating expansion.
• State the applications and problems caused by expansion.
• Explain the anomalous expansion of water and its consequences.

Summary

Most substances expand on heating because their particles vibrate more vigorously and take up more room. Gases expand most, then liquids, then solids. Expansion is exploited in the bimetallic strip and thermometers, and allowed for in expansion joints. Water is anomalous: between 0 °C and 4 °C it contracts on heating, and it is densest at 4 °C.