5.3.128 - Internal energy

Understand the concept of internal energy as the random distribution of potential and kinetic energy amongst molecules.

Use - internal energy to connect the rule to the data and decision in the question.

This matters because - internal energy determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - internal energy to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Internal energy is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.