2.4.73 - Conduction model and resistivity

Be able to use I = nqvA to explain the large range of resistivities of different materials.

Use - conduction model and resistivity to connect the rule to the data and decision in the question.

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

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

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