Chemical Compounds And Bonds

Chemical Compounds Substances formed by the combination of two or more elements Represented by chemical formulas H2O = 2 Hydrogen and 1 Oxygen atoms NaCl = 1 Sodium and 1 Chlorine atom Lower case letter means it is part of the same element

Chemical Compounds Compounds are usually very different from the elements they are made from H2O  Hydrogen and Oxygen are gases and are explosive Water is a liquid and NOT explosive NaCl  Na is a metal and reactive Cl is a poisonous gas (Used in WWI) Salt is essential for living organisms

Chemical Bonds Bonding depends on electrons (e-) in the outer most energy level Called valence electrons They are available, not covered by other electrons

Chemical Bonds Ionic Bonds Electrons are transferred from one atom to another Atoms gain or lose electrons Forms ions (“i” n“o”t “n”eutral) Lose  + charge Gain  - charge Example: NaCl

Chemical Bonds Covalent Bonds The sharing of one or more electrons between two atoms Compounds with covalent bonds are called molecules Ionic/Covalent Bonds

Chemical Bonds Intermolecular Forces The attraction of compounds to each other Ionic Forms crystals or cubes Positive/Negative Attraction

Chemical Bonds Intermolecular Forces The attraction of compounds to each other Covalent Van der Waals forces Slight attraction of molecules that are close together that hold them together Hydrogen Bonds (not an actual bond) Stronger form of van der Waals forces Attraction between hydrogen (+) and either fluorine, oxygen, or nitrogen (-)