High School Students’ Conceptual Understanding About Gas Nature and Properties in Iran

Misconceptions in science pose a significant challenge for both students and teachers, as many students accept what their teachers say as true, and textbooks can also contribute to misunderstandings. This study aimed to identify students’ perceptions of gas behavior and properties through a 60-minute diagnostic test. The sample consisted of 142 10th-grade students from a school for developing exceptional talents in Iran. The test, comprising six multiple-choice and three open-ended questions, was validated by chemistry experts and demonstrated high inter-rater reliability. It assessed students’ understanding of interparticle forces in the gas phase, the relationship between kinetic energy and gas pressure, and the nature and interactions of gas particles. The results showed that most students answered the questions incorrectly. Analyzing their explanations revealed several misconceptions, particularly regarding particulate-level concepts. Furthermore, misconceptions can be considered a form of prior knowledge, embedded within a framework of logic and justification, even if they contradict established scientific understanding.