1. Each element has a different symbol2. The formula for a compound shows the

elements in the compound 3. It also shows the ratio of the atoms of

different elements in the compound

Chemical FormulaChemical FormulaChemical FormulaChemical Formula

Chemical Formula

The Periodic TableThe Periodic TableThe Periodic TableThe Periodic Table

The Periodic Table

Chemical FormulaChemical FormulaChemical FormulaChemical Formula

Chemical Formula

Atomic StructureAtomic StructureAtomic StructureAtomic Structure

Atomic Structure

Electron shellsElectron shellsElectron shellsElectron shells

Electron shells

Electron shellsElectron shellsElectron shellsElectron shells

Electron shells

1. Word equations use the names of the reactants and products to describe a reaction

Word equationsWord equationsWord equationsWord equations

Word equations

Word equationsWord equationsWord equationsWord equations

Word equations

1. Chemical equations use the chemical formulae of the reactants and products to describe a reaction

2. The total mass of the product(s) of a chemical reaction must equal the total mass of the reactant(s)

3. Therefore chemical equations must be balanced

4. The total number of atoms of one element should be the same on both sides of the equation

Chemical equationsChemical equationsChemical equationsChemical equations

Chemical equations

Balancing equationsBalancing equationsBalancing equationsBalancing equations

Balancing equations

1. Atoms of different elements have different masses

2. The relative atomic mass (Ar) is the mass of the elements compared to the mass of a hydrogen atom

Relative atomic massesRelative atomic massesRelative atomic massesRelative atomic masses

Relative atomic masses

Relative atomic massRelative atomic massRelative atomic massRelative atomic mass

Relative atomic masses

1. The relative formula mass (Mr) is the relative mass of a molecule compared to the mass of a hydrogen atom

Relative Formula MassRelative Formula MassRelative Formula MassRelative Formula Mass

Relative formula mass

Relative formula massRelative formula massRelative formula massRelative formula mass

Relative formula mass

1. The unknown mass of a reactant or product can be worked out by using the known masses of the other reactants and products

Equation calculationsEquation calculationsEquation calculationsEquation calculations

Equation calculations

Calculations from EquationsCalculations from EquationsCalculations from EquationsCalculations from Equations

Calculations from equations

Calculations from EquationsCalculations from EquationsCalculations from EquationsCalculations from Equations

Calculations from equations