Chapter 2 interatomic bonding Flashcards
Some of the following properties are determined by electronic structure
- chemical
- electrical
- thermal
- optical
an atom contains 3 thongs
electrons
protons
neutrons
atomic number
- number of protons in the nucleus of an atoms
-
what is an amu?
atomic mass number 1/12 mass of 12C
atomic weight
wt of 6.022 * 1023 molecules or atonms
1 amu/atom = 1 g/mol
2 models of electronic structure
Bohr’s model
wave mechanical atom model
in electron structure, electrons have wavelike and particle properties. two of the wavelike characteristics are
- electrons are in orbitals defined by a probability
- each orbital at discrete energy level is determined by quantum numbers
quantum number
n =
l =
m<em>l = </em>
ms =
n = principal ( energy level shell, size, average distance)
l = subsidiary (subshell, shape)
m<em>l = </em>magnetic (number of obitals)
ms = spin
electron energy states
electron states filling orbitals
electron configurations
* quick reminder *
survey of elements
valence electrons
those in unfilled shells
are the most available for bonding and tend to control the chemical properties
ex
1s2 2s2 2p2
valence electrons
* quick reminder *
the periodic table
electronegativity
is a measure of an atom’s ability to attract shared electrons to itself.
electronegativity on the periodic table
ionic bond
type of linkage formed from the electrostatic attraction between oppositely charged ions in a chemical compound.
* quick reminder *
ionic bond
1) ionic bonding occurs between __ and __ ions
2) requires ____ transfer
3) large difference in ________ required
4) good example is _____
1) ionic bonding occurs between + and - ions
2) requires electron transfer
3) large difference in electronegativity required
4) good example is NaCI
Na (metal, unstable ) CI (nonmetal, unstable)
Na (cation,stable) + - CI(anion, stable)
* quick reference *
ionic bonding on the periodic table
cations
atom or group of atoms that bears a positive electric charge.
anions
has more electrons than protons, consequently giving it a net negative charge.
electron cloud
the system of electrons surrounding the nucleus of an atom.
* quick reference *
bond hybrization - carbon
primary bonding
involve sharing or donating electrons between atoms to form a more stable electron configuration
* quick reference *
primary bonding
secondary bonding
They are usually formed when an uneven charge distribution occurs, creating what is known as a dipole (the total charge is zero, but there is slightly more positive or negative charge on one end of the atom than on the other
* quick reference *
secondary bonding
* quick refernece *
summary bonding
Tm
melting temperature
what is the coefficient of thermal expansion represented by
α ( alpha )
thermal expansion
is the tendency of matter to change in shape, volume, and area in response to a change in temperature
types of bonding that occurs
ceramics -
metals -
polymers -
ceramics - Ionic & covalent bonding
metals - Metallic bonding
polymers - Covalent & Secondary
Large bond energy
large __
large __
small ___
Large bond energy
large Tm
large Energy
small α (thermal expansion)
Variable bond energy
moderate __
moderate __
moderate ___
Variable bond energy
moderate Tm
moderate Energy
moderate α (thermal expansion)
Directional Properties
Secondary bonding dominates
small ___
small ___
large ___
small Tm
small Energy
large α (thermal expansion)
