Final answer:
Robert is correct in saying that the strawberry frosted pop-tart is a heterogeneous mixture, as its components like crust and frosting can be differentiated and are not uniform throughout.
Step-by-step explanation:
When considering whether the strawberry frosted pop-tarts Robert and Michael are eating are a homogeneous or heterogeneous mixture, we can apply definitions and examples from chemistry. A homogeneous mixture, or a solution, is one in which the composition is uniform throughout. Materials such as air, simple syrup, and saline water are examples of homogeneous mixtures because they are visually and compositionally consistent.
On the other hand, a heterogeneous mixture is non-uniform and the different components of the mixture can be seen. Examples include cereal in milk, salad, and trail mix. Since a pop-tart consists of different components like the crust, frosting, and potentially filling, which can be visually distinguished and are not uniform throughout, it would be categorized as a heterogeneous mixture. Therefore, Robert's assertion about the pop-tart is correct.