Homogeneous and heterogeneous mixtures

[gracy]

http://dwb4.unl.edu/Chem/CHEM869B/CHEM869BInfoFiles/pubCHEM869B-Info005.html
In the last question of Quiz 1X Look at lower Ieft hand side. I chose heterogenous mixture but It was given wrong.Why?I chose heterogenous mixture because there are 4 molecules of one substance and only 3 atoms of other ,so there is no uniform composition that's why I selected heterogenous mixture.

 

[Borek]

I m not convinced I see the same problem you do. In general, when there are only few "atoms" it is hard to tell what it is intended to mean. Do they clump together?

 

[Astudious]

The idea is that in A and B, there is no overall uniformity/repeating pattern that applies consistently everywhere in the flask, whereas in C there is - therefore the mixture in C is homogeneous.

Your mileage may vary regarding the question set-up. I understand what C is trying to convey but I would say it certainly doesn't look homogeneous to me; it looks like blobs of individually-homogeneous phases, aligned in a repeating pattern. If you can do any kind of reasonable inspection of the material, you'd definitely detect the sample to have properties that oscillate from phase to phase, and the blobs certainly don't look atom-sized (and if they were, with 2 pairs in a row, I wouldn't call it homogeneous). The up-shot is that the picture should really have a lot more particles IMO.