Chemistry 11 Topics 1. Atomic Theory: The evolution and development of the atomic theory from the time of the Greek philosophers to the present day. 2. Elements and the Periodic Table: Elements are the simplest form of pure substances, each characterized by it's own atom. The elemens are arranged in the Periodic table, developed over hundreds of year as a result of the observation of the characteristics of these elements. 3. Ions : Atoms of elements that differ in the number of electrons in their shells are known as ions. 4. Isotopes: Isotopes are more than one example of an element that differ in mass due to a differing number of neutrons. 5. Ionic Compounds: Compounds which are formed when two or more ions come together and bond due to electrostatic attraction. 6. Covalent molecules: When two uncharged non-metals come together through the sharing of electrons. 7. Chemical Formulas: The representation of compounds and molecules using the chemical symbols of the atoms. 8. Chemical Equations: a representation of a chemical reaction through the combination of chemical formulas and representative symbols.