This study investigates Turkish students' (age 15 or older) interest in chemistry by analysing 1027 of their self-generated chemistry-related questions, which had been submitted to a popular science magazine. These questions were classified based on the field of interest, the cognitive level of the question, and the stimulating impetus for asking the question. In addition, gender-related patterns were noted in these three categories. Those results demonstrated that males asked overwhelmingly more questions than females in an informal setting. In general, students mostly asked questions about "states of matter and solutions" and "nuclear chemistry and chemistry of the elements." Most of the students asked for the properties of a variable and sought to learn about factual and explanatory types of information. The driving factors that led students to ask questions were mostly non-applicative stimulus. Significant differences emerged in some categories. For example, while males were more interested in comparison and causal relationships, females were more interested in specific information about properties. Moreover, while males tended toward seeking methodological information, making predictions, asking open-ended questions, and making general requests for information, females were more interested than males in factual and explanatory types of information. The implications of students' self-generated chemistry questions for science curriculum reform and teaching are discussed in this paper. Contains a combined list of notes and references.