When used the way "odds" is used in your question the two are pretty much interchangeable, but odds are usually presented as a set of numbers related by to, while chances are a set of numbers related by in, and the numbers mean different things.
When chances are presented using in, the numbers convey the number of chances out of a total. For example, 1 out of 4 means that out of 4 tries you are likely to win once.
When presenting odds using to, the numbers say how many time you're likely to win to how many times you're like to lose. For example, odds of 1 to 4 means that you are likely to win once and lose 4 times. so when the odds are 1 to 4 the chances of winning is 1 in 5.
When the chances of winning are 1 in 1,000,000 the odds are 1 to 999,999 but the difference is so small as to be all but negligible. So in things like lottery odds the terms are pretty much interchangeable.
The key point to notice is whether they use to or in. When they use in they mean out of, that is, the second numbers represents the total and not the number of losses regardless of which word (odds or chances) they use.
Put another way: To should never be used with chances
The chances are 1 to 2 - is wrong.
but, in can be used with either
The odds are 1 in 2 OR The chances are 1 in 2 - are both acceptable.
The subtle difference between the two words is this: functionality refers to the capability and suitability of a thing, whereas function refers, without value judgment, to the action a thing performs or is intended to perform.
The bridge serves the function of allowing cars and trucks to cross the river.
Traffic volume has increased tenfold since the two-lane bridge was
built. The functionality of the bridge has diminished greatly.
A new four-lane bridge is contemplated.
We have added new functionality to the software. It can now do OCR.
Best Answer
Both versions would be correct grammatically and idiomatically, though I personally prefer which.
Which is generally used when selecting from a number of items in a group. Here we are choosing from a variety of potentially suitable materials. If you are presented with a limited set of choices and asked to choose one, which is strongly preferred.
What is more open; it allows you to select from a much broader range of options. If you are presented with a broad choice, what is preferred. What is the only option when no limits have been placed on the choice.
Ex: My wife and I are trying to decide what we want to do with our weekend.
In this sentence what is the only option. Without some (even poorly defined) set of possible choices, which does not make sense.
Ex: I am at a restaurant with my wife and we have just started looking over the menu.
In my statement, what is the proper word, as all options are available. Using which here would be confusing (though perhaps I could accompany it with a gesture toward the choices on the menu and force it to make sense.) In my wife's statement, either which or what is appropriate, though which would be preferable. Moreover, if my wife used what here, she might be asking my opinion from the entire menu, whereas which limits my response to either chicken or fish.