Nov 17 2010 - The Mole

Today, we learned about the mole.

The Mole

A mole is the amount of pure substance containing the same number of chemical units as there are atoms in exactly 12 grams of carbon-12 (i.e., 6.023 X 1023).

Avogadro's hypothesis

Two equal volumes of gas, at the same temperature and pressure, contain the same number of molecules.



Atomic Mass

The atomic mass (ma) is the mass of a specific isotope of a given atom, most often expressed in unified atomic mass units.

Mass of 1 atom of the element in atomic mass units are called amu or u or daltons.

















Lithium has atomic mass of 6.9 amu.

Formula Mass

All the atoms of a formula.
























Avogadro's number

The number of particles in a mole of a substance, approximately 6.022x 10^23.