Answer:
A mixture is the blending of two or more dissimilar substances. A major characteristic of mixtures is that the materials do not chemically combine. Mixtures can be divided into those that are evenly distributed (homogeneous) and those that aren't (heterogeneous).
Explanation:
A compound is a substance composed of 2 or more chemical elements.
The model does not represent a compound because it shows two atoms of the same element combined. To be a compound the model would need to contain atoms of different element, represented by different colored balls. Therefore, the picture does not represent a compound. :)