Interpret melting point or boiling point data to decide whether a substance is pure or impure.

The focus here is Interpret melting point or boiling point data to decide whether a substance is pure or impure, not a general memory of Purity, formulations and chromatography. The approved objective is: Interpret melting point or boiling point data to decide whether a substance is pure or impure. The key evidence is single element or compound / fixed melting point, and the result to look for is purity evidence. This makes it different from nearby objectives because the answer must stay anchored to Interpret melting point or boiling point data to decide whether a substance is pure or impure, not another Chemical analysis test. Useful curriculum keywords include melting point, boiling point, and impure. Keep the method, observation, and conclusion separate so the answer does not confuse gas tests, flame tests, cation tests, anion tests, chromatography, pure substances, or formulations. A strong exam response states the test or measurement, describes what is seen, and then links that evidence directly to Pure substances.