Two powders have been mixed together to prepare a nonsterile compound. A chemical reaction is likely to have occurred if the resulting mixture is:

A homogeneous mixture indicates that the components are uniformly distributed; however, this does not necessarily imply a chemical reaction has occurred. Powders can form a homogeneous mixture through physical processes like mixing without undergoing any chemical change.

Stability refers to the ability of a mixture to maintain its composition over time without reacting further. A stable mixture does not indicate that a chemical reaction has occurred; it simply means that the resulting compounds do not change under the current conditions, which may happen even if a reaction took place initially.

The classification of a mixture as non-hazardous pertains to safety and toxicity, which is unrelated to whether a chemical reaction has occurred. A non-hazardous mixture could arise from either a physical mixing process or a chemical reaction, thus providing no indication of the reactivity of the compounds involved.