1. Chemical Bond -
a.The simplest ratio of elements in an ionic compound
that describes its composition
2. Octet Rule
b. A communal sharing of electrons between metal atoms.
3. Covalent Bond
c. The tendency of an object to form two localized regions of
opposite character; in chemistry it relates to electrical charge.
4. Ionic Bond
d. A group of atoms that maintains a constant electrical charge
while existing as a unit in a wide variety of chemical reactions.
5. Metallic Bond
e. A force of attraction that holds atoms together in compounds;
an attraction produced by the transferring or sharing of electrons
6. Polarity
f. Two atoms held together in an ion or molecule by their
attraction for the same pair of shared electrons.
7. Electrostatic Force
g. An atom tends to gain, lose or share electrons until its outer s
and p orbitals are filled with eight electrons: the electron
configuration of a noble gas.
8. Lewis Structure
h. The electrostatic attraction between two oppositely charged
ions in a solid.
9. Polyatomic Ion
i. The field force exerted by electrical charges. It may be
repulsive or attractive depending on the kinds of charges.
10. Formula Unit
j. A two dimensional diagram that uses element symbols and dots
to show the bonds between different atoms.
1. Crystal lattice
k. Electrons that can move between several different
bonds.
2. Electron Sea Theory
L. Atoms covalently bonded into a continuous three-dimensional
network: for example, diamond.
3. Delocalized electrons
m. An extensive three-dimensional structure of points or objects
that represents the regular alternating pattern of atoms or ions.
4. Network Covalent
Substance
n. A mixture of atoms of a metal with another element where
the mixture has metallic properties.
5. Alloy
o. A theory that offers an explanation of how metals bond; the
valence electrons of atoms are said to be freely shared among all
atoms. Also called the free-electron theory.
1. Chemical Bond - e
a.The simplest ratio of elements in an ionic compound
that describes its composition
2. Octet Rule
g
b. A communal sharing of electrons between metal atoms.
3. Covalent Bond
f
c. The tendency of an object to form two localized regions of
opposite character; in chemistry it relates to electrical charge.
4. Ionic Bond
h
d. A group of atoms that maintains a constant electrical charge
while existing as a unit in a wide variety of chemical reactions.
5. Metallic Bond
b
e. A force of attraction that holds atoms together in compounds;
an attraction produced by the transferring or sharing of electrons
6. Polarity
c
f. Two atoms held together in an ion or molecule by their
attraction for the same pair of shared electrons.
7. Electrostatic Force
i
g. An atom tends to gain, lose or share electrons until its outer s
and p orbitals are filled with eight electrons: the electron
configuration of a noble gas.
8. Lewis Structure
j
h. The electrostatic attraction between two oppositely charged
ions in a solid.
9. Polyatomic Ion
d
i. The field force exerted by electrical charges. It may be
repulsive or attractive depending on the kinds of charges
interacting.
10. Formula Unit
j. A two dimensional diagram that uses element symbols and dots
1. Crystal lattice - m
k. Electrons that can move between several different
bonds.
2. Electron Sea Theory - o
L. Atoms covalently bonded into a continuous three-dimensional
network: for example, diamond.
3. Delocalized electrons - k
m. An extensive three-dimensional structure of points or objects
that represents the regular alternating pattern of atoms or ions.
4. Network Covalent
Substance - L
n. A mixture of atoms of a metal with another element where
the mixture has metallic properties.
5. Alloy - n
o. A theory that offers an explanation of how metals bond; the
valence electrons of atoms are said to be freely shared among all
atoms. Also called the free-electron theory.
Bond Theories
•
•
All about the ……?
Lewis structure limitations
• Cannot show molecular shape – 2d
•
Remember sublevels?
• Azimuthal shape
•
•
•
•
•
S – 1 orbital
P – 3 orbitals
D – 5 orbitals
F – 7 orbitals
All because of electron repulsion
Bond Theories
•
Remember
sublevels?
• Azimuthal shape
• S – 1 orbital
• P – 3 orbitals
Bond Theories
•
Remember sublevels?
• Azimuthal shape
• D – 5 orbitals
Bond Theories
•
Remember sublevels?
• Azimuthal shape
• F – 7 orbitals
• All because of electron repulsion
Bond Theories
•
Covalent bonds
• 2 electrons with
opposite spin sharing
overlapping orbitals
• Electrons available to
both nuclei
• Effectively both atoms
acquire the shared
electrons
• Valence Bond Theory
Bond Theories
•
Covalent bonds
• Sigma and Pi bonds
• Sigma ∂ bonds
• Overlapping orbitals
• S (side – side) or P (endend)
• Or P – S – in line
Bond Theories
•
Covalent bonds
• Pi (π) bonds
• P orbitals out of plane
are drawn to each other
and overlap
• Double and triple bonds
Bond Theories
•
Covalent bonds
• Pi (π) bonds
• Triple bond in
molecular nitrogen
Bond Theories
•
Molecular Resonance
• Many bonds can be
represented by more
than one lewis struct.
• Should be diff. between
2 ends due to double
and single bonds – BUT
NO!!
• Completely symmetrical
•
Resonance
• Electron wave function
can occupy different
regions of a molecule at
same time
• Example - Ozone
Bond Theories
•
Odd # of valence electrons
• Extra is free radical – cause damage to cells
• Eat your fruits & veggies to combat
Bond Theories
•
Fewer than 4 pairs
• Boron – 3Ve – content with 6 to fill occupied
orbitals – Boron trifluoride
Bond Theories
•
Expanded octet
• Extra electrons occupy empty d sublevels
• Sulfur hexafluoride
Bond Theories
•
What happens when theories don’t explain
observations?
• LOX
Bond Theories
•
Time for a new theory
• E.g. valence bond theory – prohibits stray
electrons that account for certain properties of
molecule – answer? Resonance structures
• Also doesn’t account for properties of LOX
• Thus – Molecular Orbital Theory
• When bond forms, old orbitals replaced by
totally new orbitals
• Each molecule has unique orbitals – equal in # to
what sum of orbitals in original atoms
• Some encircle multiple atoms or entire molecule
Bond Theories
•
Time for a new theory
• Some encircle multiple atoms or entire molecule
• S orbital hybridization