Oyelekan, Oloyede Solomon2021-10-112021-10-112006Oyelekan, O. S. (2006): Secondary school students’ level of understanding of selected chemistry concepts in Osun State, Nigeria. The African Symposium, an online Journal of African Educational Research Network, 6(3&4), 68-75. Published by the North Carolina State University, Raleigh, North Carolina, United States of America. Available online at https://www.academia.edu/25826888/E_Learning_A_Technology_Based_Teaching_Method_For_Providing_Access_To_Sustainable_Quality_Educationhttps://uilspace.unilorin.edu.ng/handle/20.500.12484/6536A journal article on topic difficulty in School Certificate Chemistry.This study was carried out to find out the level of understanding of selected chemistry concepts by senior secondary school students in Osun state, Nigeria. Two hundred and ninety one senior secondary school III (SSIII) students from six purposively selected secondary schools were used for the study. A test item termed test of concept understanding in chemistry (TCUC) was used. It was found out that the students’ level of understanding of chemistry concepts was low and that students performed better in theoretically related concepts than in practically related concepts. Students also found it difficult to understand the following concepts: the mole concept, electrolysis, chemical formulae, equations and balancing of chemical equations, electronic configuration, preparation of salts, calculations in volumetric analysis, physical and chemical changes, and properties and identification of gases. Students however found it easy to understand acids & bases, and simple separation techniques.entopic difficultyChemistryNigeriaArticle