Navigating English Medium Instruction in Chemistry: Language as a Barrier or Bridge to Learning

Abstract English is the primary language of communication and knowledge exchange in the global scientific community. Therefore, English Medium Instruction (EMI) in undergraduate chemistry education is expected to provide students with broader access to academic resources and enhance their competitiveness for graduate studies and international careers. However, for non-native English speakers, language barriers can pose challenges, potentially hindering comprehension and decreasing learning motivation. In this study, we compared the academic performance of chemistry major students enrolled in EMI and Chinese Medium Instruction (CMI) programs who followed the same curriculum over three different enrollment years from 2022 to 2025. We examined students’ learning outcomes from introductory level courses, General Chemistry and General Chemistry Laboratory, two advanced chemistry courses, Organic Chemistry and Physical Chemistry, and a specific topic course, The Application of Group Theory in Chemistry. Notably, almost none of the EMI students had prior experience with English-based instruction in Chemistry before entering university. Despite this, our findings revealed no clear correlation between English proficiency and academic performance, and the overall achievement levels of EMI and CMI students were comparable across most courses. Interestingly, academic performance in entry-level General Chemistry emerged as a strongly associated factor with subsequent achievement in advanced chemistry courses. However, EMI students’ grades exhibited two distinct groups in some courses and a slightly higher program dropout rate. Our results also found modern technologies such as YouTube videos and ChatGPT play important roles in lowering language barriers. Drawing on Sociocultural Theory, Translanguaging Theory, and Self-Determination Theory, we interpret these findings as suggesting that learning in EMI chemistry contexts is supported by the interaction of mediational resources, translanguaging practices, and learner development. Finally, we discuss pedagogical implications and propose instructional strategies to more effectively support EMI students in undergraduate chemistry education.