This study focuses on the relationship between students' use of language resources and their conceptualisation of phenomena in producing scientific explanations in physics. The objectives are to find out if there is a general model that describe the meaning-making process, the extent that this model is applicable to various branches in physics. Successfully constructed explanations were collected through think-aloud interviews for four key topics in physics--dynamics, thermal physics, electromagnetic induction and superposition. Analysis shows that students' construction of scientific explanations in physics involves different levels of conceptualisation (macroscopic, theoretical and relational) and representations (iconic depiction, early symbols and formalism) in general. There are specific representational characteristics that are related to the nature of the concepts involved. Results show the importance of understanding how and why specific representational systems are related to particular scientific concepts and to the physical world.