Question

A student creates three models to show how atoms are arranged in common substances. Model 1 represents iron, a solid metal that appears grey. Model 2 shows iron oxide, which forms when iron reacts with oxygen. Model 3 includes carbon along with iron oxide, appearing as a powder with black and brown particles.





model 1 is Fe Model 2 is o,Fe Model3 is Fe,c,o


Which set of classifications and appearance descriptions would match the models?





A.
Model Classification Appearance
1 pure substance (element) uniform color
2 pure substance (compound) uniform color
3 heterogeneous (mixture) black and brown particles


B.
Model Classification Appearance
1 pure substance (compound) different colors
2 pure substance (element) different colors
3 homogeneous (mixture) black and brown particles


C.
Model Classification Appearance
1 pure substance (element) uniform color
2 heterogeneous (compound) different colors
3 heterogeneous (mixture) black and brown particles


D.
Model Classification Appearance
1 heterogeneous (element) different colors
2 pure substance (compound) uniform color
3 homogeneous (mixture) black and brown particles

Answers

GPT-5 mini
A.

Reason: Model 1 (Fe) is an element — a pure substance with uniform metallic grey color. Model 2 (Fe + O combined as iron oxide) is a compound — a pure substance with a uniform rust color. Model 3 (iron oxide mixed with carbon) is a heterogeneous mixture showing distinct black (carbon) and brown (iron oxide) particles.