2.2—The relative mass and charge of protons, neutrons and electrons

Know the relative mass and charge of protons, neutrons and electrons.

Use —the relative mass and charge of protons, neutrons and electrons to connect the rule to the data and decision in the question.

This matters because —the relative mass and charge of protons, neutrons and electrons determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —the relative mass and charge of protons, neutrons and electrons to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —The relative mass and charge of protons, neutrons and electrons is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.