BondingIonic versus Covalent
Ionic BondingWhat is it?Bonding between a metal and a non
metalWhat holds the bonds together? Electrostatic attraction between (+) and
(-) “charges” which results from the transfer of the electrons from the least e-neg (metal) to the most e-neg (nonmetal)
What happens to the electrons?One gets (-) the other gives (+).
Each resulting ion resembles a noble gas. The (-) resembles the noble gas in the same period. The (+) resembles the noble gas from the period above.
Types of compoundsFormula unit a single piece of the
crystal lattice or ionic compound.
ConductivityConducts electricity when molten or dissolved in solution. (When ions can move around they can conduct the electric charge)
ElectronegativityLarge electronegativity
differences – greater than 50% or about 1.7 and greater
State of MatterSolids with a very strong bond
Other characteristicsIons: elements or group of elements
that have a “charge” from an imbalance in + and –
Lewis Dot StructureThe most e- neg element gets all the
electrons show with arrow for e-transfer and ion charge created.
Covalent Bonding
What is it?:Nonmetal + nonmetalWhat holds the bonds together?Attraction between nuclei of bonding
atoms and e-Intermolecular forces: affect the bond
polarity and molecular polarityLondon Dispersion-induced dipoleDipole-dipoleHydrogen bondingNonpolar: London disp. OnlyPolar: London disp. And dip-dip with
FON to H, hydrogen bonding
What happens to the electrons?The atoms share electrons to look like
a noble gas. Nonpolar bonds share electrons evenly. Polar bonds share unevenly depending on electronegativity.
What types of compounds?Molecule is single “piece” of a
molecular compound.
Conductivity?Does not conduct (no ions – no
conduction)Electronegativity?Little electronegativity difference.
Nonpolar = less than 0.4 difference. Polar = greater than 0.4 but less than 1.7
States of Matter:All 3 states. Weaker bond: state
depends on size of molecule and intermolecular forces. Stronger than ionic bonds.
Other:Multiple bonds: C.SON group
forms a double, triple bonds.Diatomic molecules: 2 atoms
same element bonded together. BrINClHOF
Shapes:VSEPR Valence shell electron repulsion theory – shapes based on shared and lone pair electrons and central atom.
Formulas Oxidation State: Find normal charge
Lewis Dot Structure for Covalent Molecules
Why: Show how the valence electrons are arranged.
Use one dot to represent each valence electron.
A stable compound has all its atoms with a noble gas configuration. (8 v.e.)
Hydrogen follows the duet rule. (2 v.e.)The rest of the elements follow the octet
rule.Bonding pair is the one between the
symbols.
HowSum the valence electrons.Draw skeletal structure.Central atom is carbon (if present)
or the least electronegative atomUse a pair of electrons to form a
single bond between each pair of atoms.
Arrange the rest to fulfill the octet rule (except for H and the duet).
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