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

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mole chemistry.

It’s a really basic concept in chemistry. It’s used in such things as chemical reactions. You can read the numbers before each constituent in a reaction as a mole measurement.

For instance, in this reaction:

2 H2 (g) + O2 (g) >>>>>2H20 (l)

two moles of hydrogen gas react with one mole of oxygen gas to form two moles of liquid water.

Here’s a website that explains the basic mole concept::

http://antoine.frostburg.edu/chem/senese/101/moles/index.shtml

another way of expressing the number of molecules of something per liter. If you have 6.023×10^23 molecules of something in a liter, you have one mole per liter, or a molarity of 1.