define mole. What are the two things that a mole represents
Mole: The mole is a unit of measurement used to express amounts of a chemical substance, defined as an amount of a substance that contains as many elementary entities (e.g., atoms, molecules, ions, electrons) as there are atoms in 12 grams of pure carbon-12 (12C), the isotope of carbon with atomic weight 12.
A mole represents:
1. One mole of any substance contains 6.022*1023 particles (atoms, molecules, or ions). This means that one mole atom, molecule or ions of any substance contain 6.022 *1023 atoms. Example: 1 mole of CO2 will contain 6.023 X 1023 molecules of CO2.
2. One mole of a substance (atoms, molecules, ions, or particles) is that quantity in number having a mass equal to its atomic or molecular mass in grams. Example: Therefore 1 mole of Na atoms = molar mass of Na atoms = 23g.