Science Buddies: "Ask an Expert"

HOW DO THE MASS OF THE PARTS OF A MIXTURE COMPARE TO THE SUM OF THE WHOLE MIXTURE? This is a 5th Grade Science project Question...Thx

I'm not sure I understand your real question.

The mass of the mixture is the sum of the mass of each of the parts of the mixture.

Perhaps if you tell us more about the experiment you are running, we can figure out your real question.

Are you sure that this is a science project and not just a homework question?

Here's a finer point that this question might be getting at: When you combine two substances, sometimes a chemical reaction might occur. Some chemical reactions have products that are gases (O2, H2, etc), and when these escape from a liquid, the liquid's mass is reduced by the mass of the gas lost. However, have a look at the definition of a mixture:

http://en.wikipedia.org/wiki/Mixture

So, what do you think the answer is?