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19 Cards in this Set
- Front
- Back
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molecular orbitals
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*just as an atomic orbital belongs to a particular atom, a molecular orbital belongs to a molecule as a whole
*the number of molecular orbitals equals the number of overlapping atomic orbitals -bonding orbital -antibonding orbital |
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alloys
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mixtures composed of 2 or more elements, at least one of which is a metal; properties are often superior to those of component elements: harder and more durable
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Gilbert Lewis's Octet Rule of Covalent Bonding
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sharing of electrons occurs if the atoms involved acquire the electron configurations of noble gases; configurations contain 8 valence electrons (octet)
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coordinate covalent bond (e.g. CO)
:C=O:: (oxygen is stable, carbon is not) :C~=O: (oxygen donates 2 bonding electrons; ~ is coordinate covalent bond) |
(pg. 444)
covalent bond in which one atom contributes both bonding electrons; shown as arrows from atom donating electron(s) to atom receiving them |
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bond dissociation energy
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total energy required to break the bond between 2 covalently bonded atoms
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resonance structures
e.g. ozone |
structures that occur when it is possible to write 2 or more valid electron dot formulas that have the same number of electron pairs for a molecule or ion
(connected by double-headed arrows) The more resonance structures for an atom or ion, the more stable it will be. |
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diamagnetic
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substances in which all of the electrons are paired
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paramagnetic
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substances that contain 1 or more unpaired electrons
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exceptions to the octet rule
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*sometimes it is impossible to write structures that satisfy the octet rule: this occurs whenever the total number of valence electrons is odd
*e.g. NO2: 6+6+5=17 valence electrons *an unpaired electron is present in both structures *NO2 however still does not exist as a stable molecule *other exceptions include some compounds of boron and O2 |
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unshared pairs
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pairs of valence electrons that are not shared between atoms
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VSEPR Theory
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states that because electron pairs repel, molecular shape adjusts so the valence-electron pairs are as far apart as possible; unshared pairs of electrons affect the shape of molecules
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sigma bond
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a bond formed when 2 atomic orbitals combine to form a molecular orbital that is symmetrical along the axis connecting the 2 atomic nuclei
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pi bond
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a bond in which the bonding electrons are most likely to be found the in the sausage-shaped regions above and below the nuclei of the bonded atoms
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hybridization
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a process in which several atomic orbitals overlap to form the same number of equivalent hybrid orbitals
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dipole interactions
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the attractions between opposite poles of polar molecules
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electronegativity values
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in general, the electronegativity values of nonmetallic elements are greater than the electronegativity values of metallic elements
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van der Waals forces
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a term used to describe the weakest intermolecular attractions; these include dispersion forces and dipole interactions
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polar molecule
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a molecule in which one end is slightly positive and the other end is slightly negative
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sp values
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has a triple bond: sp3
all single bonds: sp has a double bond: sp2 2 double bonds: sp |
