Teacher:Given a scientific passage and an answer, generate a question for the given answer.
Teacher: Now, understand the problem? Solve this instance: Passage: Larger amounts of sulfur also come from hydrogen sulfide recovered during the purification of natural gas. Sulfur exists in several allotropic forms. The stable form at room temperature contains eight-membered rings, and so the true formula is S8. However, chemists commonly use S to simplify the coefficients in chemical equations; we will follow this practice in this book. Answer: eight-membered rings
Student:
What does the stable form of sulfur at room temperature contain?