Exam 3 Flashcards
(34 cards)
Degenerate orbitals
Electron orbitals having the same energy levels
Aufbau Principle
An electron occupies orbitals in order from lowest energy to highest.
Hund’s Rule
Degenerate orbitals are filled evenly before electrons are filled into higher energy levels.
Pauli exclusion principle
no more than two electrons can occupy the same orbital and two electrons in the same orbital must have opposite spins
Electronegativity
the ability of the atoms to attract electrons from the other elements.
Electron affinity
the amount of energy that is released when a molecule acquires an electron
Octet rule
the tendency of atoms to prefer to have eight electrons in the valence shell
Resonance Structure
a set of two or more Lewis Structures that collectively describe the electronic bonding of a single polyatomic molecule
Hybrid Structure
A Lewis structure with multiple ways of being drawn
Formal charge
the charge assigned to an atom in a molecule, assuming that electrons in all chemical bonds are shared equally between atoms, regardless of relative electronegativity.
Expanded octet
occurs when an atom is able to have more than 8 valence electrons
Free radical
contain a single unpaired electron in outer orbit
bond energy
a measure of the amount of energy needed to break apart one mole of covalently bonded gases
Longer bonds
weaker strength
VSEPR
a model used to predict 3-D molecular geometry based on the number of valence shell electron bond pairs among the atoms in a molecule or ion
how lone pair electrons can distort the bond angles in the molecular geometry
lone pairs occupy more space than bonding pairs and repel the bonding pairs, causing the bond angles to be smaller than expected.
Coulomb’s Law
predicts energy of attraction in IMF or chemical bond based on magnitude of charges and distance between particles.
dispersion (London) forces
result from fluctuations of electron distribution within neighboring atoms as they move closer together.
polar molecules
have permanent dipoles that attract each other through dipole-dipole interactions.
Hydrogen Bonding
Special dipole dipole case, Larger change in electronegativity than dipole-dipole, stronger than dipole dipole, between H-N, H-F, and H-O
All ionic compounds are
polar - strongest IMFs
High Boiling Point =
Strong IMF’s, high molecular weight, high surface area - depends on external pressure
Vapor pressure
increases and decreases with temp, but not linear, stays the same no matter the surface area
Rate of vaporization
increases with increasing temp and increasing surface area
