1. Copyright Pearson Prentice Hall Chemical Compounds Compound - two or more different elements chemically combined.

2. Copyright Pearson Prentice Hall Chemical Bonds The atoms in compounds are held together by chemical bonds.

3. Copyright Pearson Prentice Hall Chemical Bonds The main types of chemical bonds are: ionic bonds covalent bonds

4. Atoms that have _________________ have an _____________ and are called __________ They are written with a + or – next to their symbol IONS Na + Cl - gained or lost electrons electric charge

5. Copyright Pearson Prentice Hall Chemical Bonds Ionic Bonds An ionic bond is formed when one or more electrons are transferred from one atom to another. These positively and negatively charged atoms are known as ions.

6. Copyright Pearson Prentice Hall Chemical Bonds Covalent Bonds Sometimes electrons are shared by atoms instead of being transferred.

7. Copyright Pearson Prentice Hall Chemical Bonds The structure that results when atoms are joined together by covalent bonds is called a molecule.

8. MOLECULES CAN BE SHOWN IN DIFFERENT WAYS H2OH2O Water molecule: http://www.lsbu.ac.uk/water/molecule.html Other Images by: Riedell

9. WHAT HOLDS MOLECULES TOGETHER? Molecules are _____________by the ________ between ______________ regions of nearby molecules = _____________________ van der Waals forces http://www.examstutor.com/chemistry/resources/studyroom/bonding/intermolecular_forces/2_van_de_waals_forces.php held together attraction oppositely charged