The Mole

The mole is a unit, like dozen. It is equal to the number of carbon-12 atoms, in 12 grams of carbon.
1 Mole is also known as Avogadro's number. It creates a simpler way for chemists to count atoms and molecules.
Avogadro's number = 6.022 x 10²³ KNOW THIS NUMBER!!!!
Keep in mind that equal volumes of a different gasses have consistent values.


Relative Mass
Written as a comparison against the mass of another object.
  amu = atomic mass unit
Avogadro's Hypothesis
Explains that equal volumes of different gasses that are currently at the same temperature and pressure will  have the same number of particles.

Li. 7.0                    N. 14.0

=>It therefore states that if they have the same number of particles, the mass ratio is due to the mass of the particles.

Atomic Mass

Mass of the atoms of an element. Generally written in amu's, (or u's, of dalton's)

              Eg: Carbon. 16.0 amu

Formula Mass

Applies only to ionic compounds. Sum of the mass of atoms, written in amu's.

              Eg: NaCl - Na = 23.0  + Cl = 35.5 => 58.5 amu

Molecular Mass

Applies only to covalent compounds. Sum of the mass of atoms, written in amu's.

              Eg: CH4 (Methane) C = 12 + H4 = 1 * 4 = 4 => 16 amu

Molar Mass

Molar mass is the mass of one Mole of each element. (written in grams/mole)

              Eg: 1 Mole of Fe = 55.8 g/mol, 1 mole of Cs = 132.9 g/mol

Can also apply to the atomic/molecular/formula mass of any pure substance.

REMEMBER: ALL HAVE THE SAME NUMBER OF PARTICLES!