[philonossis]

Statement of the problem:
"Classify each of the following as a heterogeneous mixture, a homogenous mixture, or a pure substance."

I have a problem with a). 

a) scrambled eggs
b) apple
c) multivitamin tablet
d) distilled water.

The book answer:
a) heterogeneous mixture ----- MY ANSWER: homogeneous mixture.
b) heterogeneous mixture
c) homogeneous mixture
d) pure substance.

The book states: "A heterogenous mixture contains two or more visually distinguishable phases (parts), each of which has different properties....Because two or more phases are always present, a nonunifiorm appearance is characteristic of all heterogenous mixtures....A homogenous mixture contains only one visually distinguishable phase which has uniform properties throughout." pp. 92-93. Introduction to Chemical Principles, H. Stephen Stoker, 7th ed.

It seems to me that scrambling the eggs creates a physical mixture that is homogeneous. This seems to agree with the book's definition of a homogeneous mixture.  Scrambled eggs present a visually uniform appearance.  There are not two or more visually distinguishable phases in scrambled eggs.

Am I mistaken here?

[Matias Ekstrand]

First of all, taking scrambled eggs as an example in literature is bad.

If you look closely at scrambled eggs you can see that some parts are more white, and some are more yellow. As you can identify two different kinds of solid (more or less) parts, it is a heterogeneous mixture.

Your reasoning is good, but the problem requires you to have exactly the same mental image of scrambled eggs as they do, and there are scrambled eggs where you can't see difference between the white and yellow parts.

[philonossis]

First of all, taking scrambled eggs as an example in literature is bad.

Scrambled egg question is given by the book I am working through, so I am obligated to deal with it.

I am having trouble understanding the differences between heterogeneous and homogeneous mixture, substance, element, and compound.  It seems like it should be easy from the explanations, but when they must be applied to examples, I am stumbling.