Final answer:
A compound that is unvarying throughout to human observation is known as a homogeneous mixture, where the composition is consistent and elements or compounds are evenly distributed.
Step-by-step explanation:
If a compound looks uniform throughout to the human eye, it is referred to as a homogeneous mixture. This means that the composition of the mixture is consistent throughout, implying that the different components are mixed together so thoroughly that they are indistinguishable. For example, salt water is a homogeneous mixture because the salt is evenly distributed throughout the water. On the other hand, a heterogeneous mixture would have a non-uniform composition, where the different substances that make up the mixture are easy to distinguish, like in the case of soil with pebbles and plant material present. If the substance is not a mixture but is chemically pure, it is classified as either a compound or an element. A compound can be broken down into elements, while an element is a pure substance that cannot be broken down into simpler substances.