Chapter 3 - Bonding Flashcards
(16 cards)
Quantum numbers
Describe the size, shape, orientation, and number of atomic orbitals and element possesses
Principal quantum number, n
Describes the energy level (shell) in which an electron resides and indicates the distance from the nucleus to the electron
- Values range from 1 to ∞
Azimuthal quantum number, l
Determines the subshell in which an electron resides
- Values range from 0 to n-1
- l=0 corresponds to s, 1 is p, 2 is d, and 3 is f
Magnetic quantum number, ml
Determines the orbital in which an electron resides
- Values range from -l to +l
- s orbitals are spherical, p orbitals are dumbbell-shaped
Spin quantum number, ms
Describes the spin of an electron
- Values are -1/2 or +1/2
Bonding orbitals
Created by head-to-head or tail-to-tail overlap of atomic orbitals of the same sign and are energetically favorable
Antibonding orbitals
Created by head-to-head or tail-to-tail overlap of atomic orbitals that have opposite signs and are energetically unfavorable
Single bonds
Sigma bonds which contain 2 electrons
Double bonds
Contain on sigma bond and one pi bond
Triple bonds
Contain one sigma bond and 2 pi bonds
sp3 orbitals
- 25% s and 75% p character
- tetrahedral geometry with 109.5° bond angles
- Carbon with all single bonds
sp2 orbitals
- 33% s and 67% p character
- Trigonal planar geometry with 120° bond angles
- carbons with one double bond
sp orbitals
- 50% s and 50% p character
- Linear geometry with 180° bond angles
- Carbons with a triple bond or 2 double bonds
Resonance
Describes the delocalization of electrons in molecules that have conjugated bonds
Conjugation
When single and multiple bonds alternate, creating a system of unhybridized p-orbitals down the backbone of the molecule through which pi electrons can delocalize
