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Mr. Sudbury

� You must know the number of valence electrons for each atom. (Pattern on PT)(Pattern on PT)(Pattern on PT)(Pattern on PT)

� ElectronElectronElectronElectron----dot notation dot notation dot notation dot notation can also be used to represent molecules.

� Lewis Structures Lewis Structures Lewis Structures Lewis Structures – Formulas in which atomic symbols represent nuclei and inner-shell electrons, dot pairs or dashes represent electron pairs SHARED in covalent bonds

� HHHH2222

� F2

� A single bond is a covalent bond produced by the sharing of one pair of electrons between atoms

� The electrons that are not used in bonding are called the unshared pair or lone pair.

� C2H4

� A double bond is a covalent bond produced by the sharing of two pairs of electrons between atoms

� N2

� A triple bond is a covalent bond produced by the sharing of three pairs of electrons between atoms

� VSEPRVSEPRVSEPRVSEPR – “Valence Shell Electron-Pair Repulsion”

� VSEPR Theory VSEPR Theory VSEPR Theory VSEPR Theory states that the repulsion between the sets of valence-level electrons surrounding an atom causes these sets to be as far apart as possible.

� VSEPR explains VSEPR explains VSEPR explains VSEPR explains why compounds take the shape they do. (Their molecular geometry.)

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� Hybrid means something that is created from two different sources.

� Hybridization in atoms is when two or more atomic orbitals of similar energies on the same atoms combine to produce new orbitals of equal energies.

� Molecular Geometry is the study of the shapes that molecules make when they bond.

� Also, studying if a compound is polar or nonpolar.

� Electron Dot Diagrams

� Lewis Diagrams for compounds

� VSEPR – Molecule shapes