calculations

• What is relative atomic mass (Ar)?

  Weighted average of the masses of atoms
• What is relative formula mass (Mr)?

  Sum of relative atomic masses in a formula
• What is Avogadro’s number?


  $6.022 \times 10^{23}$
• What is percentage composition?

  Mass of each element as a percentage of total mass
• How do you calculate reacting masses?

  Using the mole concept and balanced equations
• What is a limiting reagent?

  The reactant completely consumed in a reaction