C3- Quantitative chemistry

• Relative atomic mass (Ar)

  The average mass of the atoms of an element compared with carbon- 12 (which is given a mass of exactly 12). The average mass must take into account the proportions of the naturally occurring isotopes of the element.
• Relative formula mass (Mr)

  The total of the relative atomic masses, added up in the ratio shown in the chemical formula, of a substance.
• Mole

  The amount of substance in the relative atomic or formula mass of a substance in grams.
• Avogadro constant

  The number of atoms, molecules, or ions in a mole of any substance (I.e.. 6.02 x 10^23)
• Concentration

  The mass of a substance per volume (g/cm^3)
• Mass

  Amount of material in an object measured in kg.
• Conservation

  Nothing lost or gained (e.g. Atoms)
• Balanced symbol equation

  A symbol equation in which there are equal numbers of each type of atom on either side of the equation.
• Ratio

  A way of comparing two or more quantities, showing how many times one is contained within the other.
• Limiting reactant

  The reactant that is used up first in a reaction.