Chemical Bonding Flashcards
Polar
Covalent bond with uneven distribution of charge
Ionic Bond
Result of the electron attraction between cations and anions; electrons transfer
Ionic character (%)
Determined by electronegativity values
- greater than 50%=ionic
- 5-50%=polar covalent
- below 5%=non-polar covalent
Determining % Ionic Character
A-B=[(E1-E2)/E1]x100
A=more electronegative element
OR ionic=1.7-3.3 difference
polar covalent=0.3-1.7
non-polar covalent= 0.0-0.3
Molecule
Neutral group of atoms linked by covalent bonds
Diatomic Molecule
Molecule made up of two atoms
Non-Noble Gases
Occur as covalent diatoms (H2, N2, O2, F2, & Cl2, as well as Br2 and I2
Molecular Compound
Simplest units are molecules
Octet Rule
Formation of compounds occurs so that each atom ends up with an octet of electrons in its highest energy level
Bond Length
Average distance between two bonded atoms; occurs at the minimum potential energy
Kernel
Nucleus and full levels not involved in bonding (everything but valence)
Bond Energy
Energy required to break a chemical bond and form neutral, isolated atoms
Polyatomic Ions
Group of covalently bonded atoms that remains charged
VSEPR Theory
(Valence Shell Electron Pair Repulsion) Repulsion between the sets of valence electrons surrounding an atom causes these sets to be oriented as far apart as possible
Shape
Refers to position of atoms in the molecule
Hybridization
Mixing of two or more atomic orbitals of similar energies on the same atom to make a new orbital of equal energy
Intermolecular Forces
Forces of attraction between molecules
Dipole
Molecular condition where equal but opposite charges are separated by short distance
Dipole Forces
Force of attraction between polar molecules
Hydrogen Bonding
Force of attraction by hydrogen atom, that is bonded to a highly electronegative atom, toward unshared electrons of a similar nearby molecule
London Dispersion Forces
Attractions resulting from the constant motion of electrons and the creation of instantaneous dipoles
Formula Unit
Simplest collection of atoms from which the ionic formula can be established
Empirical Formula
Any chemical formula that shows the simplest whole number ratio between atoms in a compound
Crystal Lattice
Orderly arrangement of ions in an ionic compound that creates a 3D structure
Lattice Energy
Energy released when one mole of an ionic crystal is formed from gaseous ions. Negative values in kJ/mol indicates energy is released when crystals form.
Metal
Mobile electrons form a sea that hold the metal together, accounts for conductivity, malleability, and ductility. Bond strength is measured by enthalpy of vaporization in kJ/mol; more heat absorbed to vaporize means that a stronger metallic bond exists.
AB2
Linear, like CO2
AB2E2
Bent, like H2O
AB3E
Trigonal pyramid, like ammonia
ABE System
Determines molecular geometry
