A guided inquiry lesson intended to support the linguistic and conceptual development of English language learners (ELLs) in a small, cotaught, high-needs secondary setting is presented. Collaborative groupings based on language and content ability coupled with an emphasis on student-student discourse and a hands-on investigation appeared to contribute to the positive outcomes that were observed on a written assessment. The phenomenon of code switching, where students spoke in their native tongue at times of apparent high cognitive demand, was observed. Implications of the approach used in this lesson for teaching chemistry in culturally diverse settings are discussed.