Question

consider the following situation:
a scientist is given an unknown material.
--he first tries to separate it into different parts, but it all looks the same
--next, he tries to break it down into simpler chemicals, but no matter how hard he tries, he cannot break it down.
what is the most likely identity of the material?
it is probably a chemical compound, like salt
it is probably a heterogeneous mixture of compounds
it is probably a chemical element, like gold
it is probably a homogeneous mixture of elements

Explanation:

A material that is uniform (cannot be separated into different parts) and cannot be broken down into simpler chemicals is a chemical element, as elements are pure substances with no simpler components.

Answer:

It is probably a chemical element, like gold