compounds with the same molecular formula that differ in connection, yielding different physical properties and different names.
tetra- , tri- , di- , mono-
Tendency to form a certain number of bonds.
terta- = four
tri- = three
di- = two
mono- = one
Bond resulting due to two atoms sharing a pair of electrons.
What are the 3 forces to account for when atoms approach each other?
1) the force of repulsion between the two negatively charged electrons
2) the force of repulsion between the two positively charged nuclei
3) the forces of attraction between the positively charged nuclei and the negatively charged electrons
1Å = ___ m
Tendency of atoms to form the necessary number of bonds in order to reach a full outer shell.
pair of unshared electrons
charge associated with any atom that does not exhibit the appropriate number of valence electrons.
What are the two tasks in identifying a formal charge?
1) Determine the appropriate number of valence electrons for an atom.
2) Determine whether the atom exhibits the appropriate number of electrons.
What are the 3 bond categories?
2) polar covalent
withdrawal of electrons towards a much more electronegative atom
science of the very small; study of the particle and wave-like properties of electrons
electrostatic potential maps
3D, rainbow-like images that represent a visualization of partial charges
probability of finding an electron in a particular region of space
region of space that can be occupied by electron density
Locations where the value of ψ is zero
The more nodes an orbital has, the _____ its energy.
Orbitals with the same energy level
What are the 3 principles involved in determining the order that orbitals are filled?
- Aufbau Principle
- Pauli Exclusion Principle
- Hund's rule
The lowest energy orbital is filled first.
Pauli Exclusion Principle
Each orbital can accommodate a maximum of two electrons that have opposite spin
When dealing with degenerate orbitals, such as p orbitals, one electron is placed in each degenerate orbital first, before electrons are paired up
A covalent bond is formed by the overlap of _______ ________.
What 2 theories describe atomic orbital overlap?
Valence bond theory and molecular orbital (MO) theory.
produces a wave with larger amplitude
results in waves canceling each other, which produces a node
valence bond theory
a bond is simply the sharing of electron density between two atoms as a result of the constructive interference of their atomic orbitals
sigma (σ) bond
all single / first bonds; electron density is primarily located on the bond axis
All single bonds are _____ bonds.
Molecular Orbital Theory
atomic orbitals are mathematically combined to produce new orbitals
- linear combination of atomic orbitals
- mathematical method to determine molecular orbitals
new orbital formed from combination of atomic orbitals; applies to entire molecule
lower energy molecular orbital;
result of constructive interference of the original atomic orbitals;
electrons prefer due to lower energy
higher energy molecular orbital;
result of destructive interference;
has 1 node
highest occupied molecular orbital;
highest energy orbital among occupied orbitals
lowest unoccupied molecular orbital;
the lowest energy orbital from among the unoccupied orbitals
average of one s orbital and three p orbitals;
gives us four orbitals
average of one s orbital and 2 p orbitals;
produces three bonds
average of one s orbital and one p orbital;
produces two bonds
pi (π) bonds
overlapping p orbitals formed between two atoms that already have a σ bond
Rank single, double, and triple bonds in order of strength from strongest to weakest.
___ > ___ > ___
triple > double > single
σ bonds + lone pairs;
used to determine geometry
valence shell electron pair repulsion;
repulsion of electron pairs in order to achieve maximal distance from each other;
Which type of electron interaction is a stronger repellent?
1. lone pair
2. lone pair
Do pi (π) bonds affect the steric number?
Y or N
dipole moment (µ)
indicates polarity when induction is occuring
molecular dipole moment
vector sum of dipole moments;
takes into account both the magnitude and the direction of each individual dipole moment
attractive forces between individual molecules
result of the attraction between opposite charges
dipole - dipole interactions
interactions based on momentary dipole moments between atoms
specific type of dipole - dipole interaction;
occurs when a hydrogen atoms is bonded to an electronegative atom and induction takes affect;
can interact with a lone pair from another electronegative atom
London Dispersion Forces
when a center and negative charge of an atom do not line up, creating a fleeting dipole moment, which can cause similar circumstances in surrounding atoms
More Surface Area =
1. more LDF, higher BP
2. fewer LDF, lower BP
3. fewer LDF, higher BP
4. more LDF, lower BP
1. more LDF, higher BP
Branching a molecule gives it more or less surface area?
less surface area
principle of solubility
like dissolves like
attracted to water
repelled by water
simple cell formed with nonpolar tails facing in and polar heads facing out;
ex. used to surround nonpolar oil molecules, while polar heads allow solubility