Structure and Bonding Flashcards
Definitions
- protons and neutrons
- electron cloud
- mass (nucleus)
- volume (electron)
Atomic Structure
two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons
Isotopes
electron location unknown but electron density is known
Quantum Mechanical Model
electron will be in a certain region of space (orbital) at a given instant
Electron Density
Electrons do not circle around the nucleus in fixed orbits but rather,
in ________.
Orbitals
Each orbital has a characteristic _____and ____ (energy).
Shape and Size
used to described orbitals
Quantum Numbers
lowest-energy orbitals fill up first
Aufbau Principle
If two or more empty orbitals of equal energy are available, one electron occupies each with spins parallel until all orbitals are half-full,
Hund’s Rule
Only two electrons can occupy an orbital, and they must
have opposite spins
Pauli’ Exclusion Principle
there is a limit to the precision with which certain pairs of physical properties can be simultaneously known
Heisenberg’s Uncertainty Principle
Electron BELOW the outermost shell
Core Electrons
Electrons IN the outermost shell
Valence Electrons
An attractive force between two ions or between two atoms
Chemical bond
Why do chemical bonds form?
more stable and lower in energy
How do chemical bonds form?
Octet Rule
Chemistry of main-group elements is governed by their tendency to
take on the electron configuration of the nearest noble gas.
Octet Rule
Attractive forces between opposite charges
Electrostatic Attraction
formed in electrostatic attraction
formed in transfer of electrons
reaction of metals with nonmetals
Ionic Bond
Compounds formed by ionic bonds
Ionic Compound
Bond formed as a result of sharing electrons between two nuclei
Covalent Bond
Compounds formed by covalent bonds
Molecular compounds
Measure of the ability of an atom to pull the bonding electrons toward itself
Electronegativity
covalent bond between atoms with SAME electronegativity
Nonpolar covalent bond
covalent bond between atoms with DIFFERENT ELECTRONEGATIVITIES
Polar covalent bond
< 0.4
pure covalent
between 0.4 and 1.8
Polar covalent
> 1.8
ionic
a pair of equal and oppositely charged poles separated by a DISTANCE
Dipole
Measure of Dipole
Dipole moment
magnitude of the charge on either atom x distance between the two charges
Dipole moment
electron-dot structures
Lewis Structures