2. Atoms, Molecules and Moles   Previous PageNext Page
     Molecules, Molecular Weight, and Moles

This number can be measured experimentally by several independent methods, using gases, liquids, and crystals, and has been found to have the value

N = 602, 209, 430, 000, 000, 000, 000, 000
N = 6.022 x 10 molecules

As an illustration of how many molecules there are in one mole, if each molecule were represented by an ordinary glass marble, and these marbles were packed as closely together as possible, one mole of marbles would cover the entire United States with a layer seventy miles deep!

All these molecules are contained in only 2.016 grams of hydrogen gas (a balloon 35 cm in diameter), 18.015 grams of water (half of a one ounce shot glass), or a cube of rock salt 3 cm on a side.

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