{"knowledge_schema": {"broad_category": "Chemistry \u2192 Isotopes and Reactions \u2192 Organic Chemistry", "refinement": "This problem involves understanding the properties of substances, their isotopes, and the reactions they undergo, particularly in organic chemistry contexts.", "specific_scope": "The focus is on Substance Z, its isotopes, and the resulting products from its reactions, including the calculation of atomic masses of its constituent elements.", "goal": "Determine the combined atomic masses of the lightest and heaviest elements in Substance Z, considering all isotopes."}, "summary": "This problem is rooted in chemistry, specifically in the study of isotopes and their reactions in organic chemistry. It requires an understanding of the properties of Substance Z, which reacts with liquid Q to produce gas R and solid S, and involves calculating the combined atomic masses of the lightest and heaviest elements present in Substance Z. The answer to the question is 35, indicating the specific atomic masses of the relevant isotopes."}