Chapter 8 Review (Nicholas Delor)
Ionic vs Molecular Compounds
Both
Molecular
Groupings of atoms
Octet rule
Bonds
Compounds
2 or more nonmetals
Shares electrons
Gases/Liquids at room temp.
Atomic molecule Br2I2N2Cl2O2F2
Low melting point
Ionic
High melting point
Solids/molecular liquids at room temp.
Electricity conductor
Transfers electrons
Metal/Nonmetal
VSEPR Theory and Molecular Geometry
Tetrahedral (CH4)
Trigonal-pyramidal (NH3)
Bent or Angular (ONF)
Bent or Angular (H20)
Trigonal-planar (BF3)
Trigonal bipyramidal (PCl5)
Linear (BeF2)
Octahedral (SF6)
Definitions
Single Covalent Bond - Two atoms held together by sharing a pair of electrons.
Structural Formula - Represents the covalent bonds by dashes and shows the arrangement of covalently bonded atoms.
Octet Rule - In covalent bonds, electron sharing usually occurs so that atoms attain the electron configuration of noble gases. This can be either filling an element by having 2 or 8 valence electrons. Elements from the nonmetals and metalloids will combine to form covalent bonds.
Unshared pair - A pair of valence electrons that are not shared between atoms.
Lewis Dot Diagrams - Element Symbol surrounded by dots indicating the number of electrons in the outermost energy level of the atom (AKA, Valence Electrons).
Covalent Bond Variations
Double & Triple Covalent Bonds
Coordinate Covalent Bond - A covalent bond in which one atom contributes both bonding electrons. In a coordinate covalent bond, the shared electron pair comes from one of the bonding atoms.
Atoms form double or triple covalent bonds if they can attain a noble gas structure by sharing two pairs or three pairs of electrons.
Double Covalent Bond - A bond that involves two shared pairs of electrons.
Triple Covalent Bond - A bond that involves three shared pairs of electrons.
Electronegativity Values for Selected Elements
Hydrogen (H) - 2.1
Lithium (Li) - 1.0, Beryllium (Be) - 1.5, Boron (B) - 2.0, Carbon (C) - 2.5, Nitrogen (N) - 3.0, Oxygen (O) - 3.5, Fluorine (F) - 4.0
Sodium (Na) - 0.9, Magnesium (Mg) - 1.2, Aluminum (Al) - 1.5, Silicon (Si) - 1.8, Phosphorus (P) - 2.1, Sulfur (S) - 2.5, Chlorine (Cl) - 3.0
Potassium (K) - 0.8, Calcium (Ca) - 1.0, Gallium (Ga) - 1.6, Germanium (Ge) - 1.8, Arsenic (As) - 2.0, Selenium (Se) - 2.4, Bromide (Br) - 2.8
Rubidium (Rb) - 0.8, Strontium (Sr) - 1.0, Indium (In) - 1.7, Tin (Sn) - 1.8, Antimony (Sb) - 1.9, Tellurium (Te) - 2.1, Iodine (I) - 2.5
Caesium (Cs) - 0.7, Barium (Ba) - 0.9, Thallium (Tl) - 1.8, Lead (Pb) - 1.9, Bismuth (Bi) - 1.9