2.11—Ideas about electronic structure developed from: i an understanding that successive ionisation energies provide evidence

Know that ideas about electronic structure developed from: i an understanding that successive ionisation energies provide evidence for the existence of quantum shells and the group to which the element belongs ii an understanding that the first ionisation energy of successive elements provides evidence for electron sub-shells.

Use —ideas about electronic structure developed from: i an understanding that successive ionisation energies provide evidence to connect the rule to the data and decision in the question.

This matters because —ideas about electronic structure developed from: i an understanding that successive ionisation energies provide evidence determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —ideas about electronic structure developed from: i an understanding that successive ionisation energies provide evidence to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Ideas about electronic structure developed from: i an understanding that successive ionisation energies provide evidence is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.