TASK DEFINITION: Given a scientific passage and an answer, generate a question for the given answer.
PROBLEM: Passage: Secondary pollutants form from chemical reactions that occur when pollution is exposed to sunlight. Answer: sunlight

SOLUTION: Secondary pollutants form from chemical reactions that occur when pollution is exposed to what?

PROBLEM: Passage: Carbon has four valence electrons, so it can achieve a full outer energy level by forming four covalent bonds. When it bonds only with hydrogen, it forms compounds called hydrocarbons. Answer: four

SOLUTION: How many valence electrons does carbon have?

PROBLEM: Passage: A crystal contains a three-dimensional array of alternating positive and negative ions. The precise pattern depends on the compound. A crystal of sodium chloride, shown here, is a collection of alternating sodium and chlorine ions. Answer: compound

SOLUTION:
What does the precise pattern of a crystal depend on?