Bonding and Chemical Interactions Flashcards
Octet Rule
an atom will bond until it has a full outermost shell and it wants to have a configuration similar to a noble gas
Stable Smaller Octets
H (2), He (2), Li (2), Be (4), B (6)
Expanded Octet:
atoms found in the or beyond the third period can have more than 8 valence electrons because some of there electrons can be in a d orbital
can have more than 4 bonds in a lewis structure
Lewis Structure
The chemical symbol of an element surrounded by dots that represent one of the s or p valence electrons
Formal Charges
the charge an atom would have if the electrons in the bonds were shared equally
Polar Covalent Bond
bonding electron pair is not shared equally, but pulled toward the more electronegative atom
Polarity of Molecules
Depends on the polarity of the constituent bonds and on the shape of the molecule. (vector addition to determine dipole moment)
Linear
Regions of Electron Density: 2
Angle: 180
Trigonal Planar
Regions of Electron Density: 3
Angle: 120
Tetrahedral
Regions of Electron Density: 4
Angle: 109.5
Trigonal Bipyramidal
Regions of Electron Density: 5
Angle: 180, 120, 90
Octahedral
Regions of Electron Density: 6
Angle: 180, 90
Complex Ion (Coordination Compound)
A lewis acid-base adduct with a cation bonded to at least one election pair donor. Donor molecules are celled ligands and use coordinate covalent bonds. The central cation can be bonded to the same ligand multiple times in chelation.
Hydrogen Bonding
the partial positive charge of the hydrogen atom interacts with the partial negative charge located on the electronegative atoms or nearby molecules
Dipole-Dipole Interactions
polar molecules orient themselves such that the positive region of one molecule is close to the negative region of another molecule
Dispersion Forces
The bonding electrons in covalent bonds may appear to be equally shared between two atoms but at any particular point in time they will be located randomly throughout the orbital, which permits unequal sharing of electrons, causing transient polarization and counterpolarization of the electron clouds of neighbouring molecules inducing the formation of more dipoles
Ionic Bonding
electrons from an atom with low ionization energy are transferred to an atom with high electron affinity (usually a metal to a nonmetal), characterized by lattice structures
Covalent Bonding
electron pair is shared equally between to atoms
Coordinate Covalent Bonding
electron pair is donated only by one atom in the pair
Preferences in Resonance Structure
small or no formal charge
less separation between opposite charges preferred
negative charges on more electronegative atoms preferred
