{"knowledge_schema": {"broad_category": "Chemistry \u2192 Organic Chemistry \u2192 Isotopes and Reactions", "refinement": "This problem involves understanding the properties of substances, their isotopes, and the reactions they undergo, particularly focusing on the atomic masses of elements involved in a specific substance.", "specific_scope": "The task is to identify the cumulative atomic masses of the lightest and heaviest elements present in Substance X, based on the information provided about its isotopes and reactions.", "goal": "Calculate the cumulative atomic masses of the lightest and heaviest elements in Substance X to determine the correct answer from the given candidates."}, "summary": "This problem requires knowledge of chemistry, particularly isotopes and their reactions. Substance X contains a heavier isotope of one of its elements and reacts with liquid Y to produce gas W and precipitate G. The task is to calculate the cumulative atomic masses of the lightest and heaviest elements in Substance X, considering all isotopes. The candidates provided represent potential answers based on the atomic masses of elements involved."}