Molecular Geometry

Molecule

2 or more elements that are chemically combined

Compound

2 or more different elements chemically combined

London Dispersion Forces

Found in all molecules

• very weak

• Only IMF in nonpolar molecules

• attraction due to temporary dipoles

Dipole-Dipole Forces

Found in all polar molecules

Has partial positive and negative charges that attract each other.

Hydrogen Bonding

Very strong dipole-dipole forces (Hydrogen has FON)

• strongest IMF possible in polar covalent molecules

Ion-Dipole/Molecule-Dipole

Attractions between an ion and a water molecule that is stronger than an ionic bond

• responsible for ionic compounds dissolving in water

Ion

Charged particle formed when an atom gains e- or loses e-

Isotope

Elements w/ the same number of protons but different number of neutrons

Ground State

Most stable or lowest energy arrangement of electrons

• Electrons fill the lowest energy level first

• Fill each new orbital w/1 electron before beginning to pair

Linear

• 2 bonding pairs

• 180 degrees

Trigonal Planar

• 3 bonding pairs

• 120 degrees

Bent

• 2 bonding pairs

• 1 nonbonding pair

• 120 degrees

Tetrahedral

• 4 bonding pairs

• 109.5 degrees

Trigonal Pyramidal

• 3 bonding pairs

• 1 nonbonding pair

• 109.5 degrees

Bent

2 bonding pairs

2 nonbonding pairs

109.5 degrees or 104.5

Molecular Geometry

Describes what molecule actually looks like

Electronic Geometry

Takes into account all charged groups (Bonds+Lone pairs)

Polar

uneven, asymmetric distribution of charge/atoms

Nonpolar

Even, symmetric distribution of charge/atoms

Relationship between polarity + solubility

“Like dissolves Like”

• substances dissolve in other substances w/similar IMFs

Universe favors low energy and high entropy

Transferring electrons (IONIC)

Metal (Lose electrons easily) + Nonmetal (attract electrons, hold them tightly)

Sharing Electrons (COVALENT/MOLECULAR)

Nonmetals (similar electronegativity and Ionization energy)

• Difference in electronegativity determines polarity

Mobile Electrons (METALLIC)

Metals only (Sea of electrons)

Bonds Breaking

Equation - H2 + energy = 2H

Energy - Endothermic

Stability - decreasing

Like - Divorce

Bonds Forming

Equation - 2H = H2 + energy

Energy - Exothermic

Stability - Increases

Like - Marriage