What is a way to put alloy and concentration into a sentence that helps to explain solutions?
Here is a link that will give you several definitions and examples of alloys. Although none use the word concentration, I think the one that explains steels (the word percentages is used) might be something you could use with the words "different concentrations" substituted for "percentage".
Oops, forgot the link.
http://www.google.com/search?q=define%3Aalloy&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a
To explain solutions using the terms "alloy" and "concentration" in a sentence, you can say:
"In chemistry, a solution is formed when a solute (like an alloy) is dissolved in a solvent, resulting in a homogeneous mixture. The concentration of the alloy in the solution refers to the amount of solute present relative to the amount of solvent."