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20 Cards in this Set
- Front
- Back
What are Valence Electrons?
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Electrons occupying the outermost energy level
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What is the difference between an ionic and covalent bond?
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ionic bonds transfer e-, while covalent share e-
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What is the octet rule?
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Main group A elements acquire a complete octed in their outershell during bonding. Transition metals do not follow this. For hydrogen only 1 electron the duet rule applies.
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Shared Electron =
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Octet Electrons
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What are resonance structures?
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structures in which double bonds and or triple bonds between atoms make for structure that resonates between two or three simple structures.
- not differnet molecules - arise when two lewis structures are equally possible - only electrons can be shifted. atoms cannot be moved |
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What are some exceptions to the octet rule?
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Hydrogen- Duet Rule
Boron- 6 electrons Be- 4 electrons Odd electron species- free radiacals Paramagnetic |
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What is a free radical?
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molecule with an odd number of electrons.
- do not have completed octet and often undergo vigorous redox reactions. - can kill cells if produced within |
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Valence Shell Repulsion Theory
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the idea geometry of a molecule is determined by the way the electron pairs orient themselves in space.
- the orientation of e- pairs arises from electron repulsions - the electron pairs spread out so as to minimize repulsion |
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A-X-E notation
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A= central atom
X= terminal atom E= lone pair |
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Linear
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Bond angles 180
ex: Co2 o=c=o SP |
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Bent (Angular)
degrees-- Geometry -- Hybridization-- |
AX2 E2 - Geometry
Sp3 - Hybridization 104.5- Degrees Polar |
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Triagonal Planer
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AX3 - Geometry
120 degrees Sp2 - Hybridization |
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Trigonal Pyramidal
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Ax3E- Geometry
Hybridization- Sp3 107- degreez |
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T-Shaped
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Ax3E2 - Geometry
Hybridization -sp3d |
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Tetrahedral
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AX4
Sp3 109.5 |
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Bond angles in an octahedral
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90 in and and out of plane
180 between diametrically oposite atoms and the central atom. |
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Valence Bond Theory
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unpaired electrons from one atom pair with unpaired electrons from another atom and give rise to chemical bonds
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Sigma bonds
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all single bonds
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Double
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1 pie bond
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Triple
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1 sigma 1 pie.
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