The Mole By Students, Class of 2000

Skills Page

The Mole
By Steven Piacente, John Schwartz and Aldo Terranova, Class of 2000

III The Mole

The mole is a unit used in chemistry to measure the amount of a substance.

One mole of any substance contains about 602.214 billion trillion of the

elementary entities that make up the substance. These entities can be

molecules, atoms, ions, electrons or other subatomic particles, or groups

of particles. The large number is called the Avogadro's constant, in honor

of Italian physicist Amedeo Avogadro. The mole is a base unit in the

metric system of measurement. The symbol for the mole is mol. The mass in

grams of 1 mole of a substance is the same as the number of atomic mass

units in one elementary entity of that substance. One atomic mass unit is

1/12 the mass of one atom of Carbon-12. Carbon-12 is the isotope of carbon

whose atomic nucleus contains 6 protons and 6 neutrons. Therefore, one

atom of carbon-12 has a mass of 12 atomic mass units, and 1 mole of

carbon-12 has a mass of 12 grams.