Mole Definition: a chemical mass unit, defined to be 6.022 x 1023molecules, atoms, or some other unit. The mass of a mole is the gram formula mass of a substance.
Examples: 1 mole of NH3 has 6.022 x 1023molecules and weighs about 17 grams. 1 mole of copper has 6.022 x 1023atoms and weighs about 63.54 grams.
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