A homogeneous mixture is uniform, meaning... Neat and spread evenly throughout. The substances are fairly spread out throughout the mixture. An example my teacher used was Kool-Aid. You mix it and spread the mixture out evenly throughout the drink. A heterogeneous mixture is messy... Like a fruit salad. It's not orderly. The fruit and leaves in it are spread messily.
Also, a mixture (as you probably already know) can be separated without a means of using chemicals. You can separate things like a salads parts. Unlike, oxygen for example, which would be a compound, because you can't separate the elements within it (which I believe is hydrogen and carbon dioxide)
