A question of substances

Expert chemists have a wealth of conceptual understanding from which to draw to interpret chemical phenomena. Indeed, we use some fundamental concepts so intuitively that we tend to overlook their importance to a new learner. Chemical substances are a classic example. Students need to comprehend that a substance is ‘a unique kind of stuff, identified by certain invariable properties’. And that it can be either an element or a compound. A student’s understanding of this is crucial for them to go on and succeed.