3.P15—Tests for ions and gases

Recall and interpret observations relating to tests for ions and gases in Units 1 and 2.

Use .p15—tests for ions and gases to connect the rule to the data and decision in the question.

This matters because .p15—tests for ions and gases determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply .p15—tests for ions and gases to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: .P15—Tests for ions and gases is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.