2Lesson1 :Covalent Bonding Covalent bonds: atoms held together by sharing electrons.Molecules: neutral group of atoms joined together by covalent bonds.Diatomic molecule: molecule consisting of 2 atoms. Remember them: F2, Cl2, I2, Br2, H2, N2, O2Molecules tend to have lower melting and boiling points than ionic compounds.YouTube - Making Molecules with Atoms
3Molecular FormulaShows how many atoms of each element a molecule contains.Naming binary molecular compoundsComposed of two nonmetals; often combine in more than one way. Ex. CO and CO2Prefixes are used to name binary molecular compounds.PrefixMono-Di-Tri-Tetra-Penta-Hexa-Hepta-Octa-Nona-Deca-Number12345678910
4Binary Compounds Containing Two Nonmetals To name these compounds:give the name of the less electronegative element first with the Greek prefix indicating the number of atoms of that element presentAfter give the name of the more electronegative non-metal with the Greek prefix indicating the number of atoms of that element present and with its ending replaced by the suffix –ide.Do not use the prefix mono- if required for the first element.
7Naming Binary Compounds YesMetal Present?NoYesMoleculeUse GreekPrefixesDoes the metal formmore than one cation?NoYesIonic compound (cation has morethan one charge) Determine theCharge of the cation; use a Romannumeral after the cation name.Ionic compound (cation hasone charge only)Use the elementname for the cation.Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 98