2.4—The atomic number and the mass number to determine the number of each type of subatomic particle in an atom or ion

Be able to use the atomic number and the mass number to determine the number of each type of subatomic particle in an atom or ion.

Use —the atomic number and the mass number to determine the number of each type of subatomic particle in an atom or ion to connect the rule to the data and decision in the question.

This matters because —the atomic number and the mass number to determine the number of each type of subatomic particle in an atom or ion determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —the atomic number and the mass number to determine the number of each type of subatomic particle in an atom or ion to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —The atomic number and the mass number to determine the number of each type of subatomic particle in an atom or ion is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.