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25 Cards in this Set
- Front
- Back
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Ionic Bonding |
Bonding between a metal and an nonmetal, where an electron transfer takes place
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Covalent Bonding
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Bonding between two nonmetals, where an electron is shared between two atoms. The shared electron is considered localized between the two atoms as it spends most of its time between them
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Metallic Bonding
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Bonding between two metals, where a valence electron is pooled between all the atoms., into a "sea" of electrons that "flows" between metal-ion cores. The electrons are said to be delocalized.
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Lewis Electron-Dot symbol
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The element symbol represents the nuleus and inner electrons; the surrounding dots represent the valence electrons. Te pattern of dots is the same for elements within a group.
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Octet Rule
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When atoms bond, they lose, gain, or share electrons to attain a filled outer level of eight (or two) electrons.
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Covalent Bond
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The bond formation arises from the balance between nucleus-electron attractions and electron-electron as well as nucleus-nucleus repulsions. Bond formation results in greater electron density between the nuclei.
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Bonding pairs or shared pairs
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Each atom forming a covalent bond "counts" the shared electron as belonging entirely to itself and this shared or bonded pair is represented by a pair of dots or a line.
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Lone pair or unshared pair
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An outer-level electron pair not involved in bonding is called a lone pair or unshared electron.
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Bond order
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The bond order is the number of electron pairs being shared by any pair of bonded atoms.
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Single bond
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It consists of a single bonding pair of electrons and has the bond order of 1.
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Double bond
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It consists of two pairs of bonding electrons or 4 electrons being shared and has the bond order 2.
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Triple bond
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It consists of three bonding pairs, two atoms share 6 electrons and so the bond order is 3.
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Bond energy (BE)
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Also called bond strength or bond enthalpy is the energy required to overcome the mutual attraction between two covalent atoms, and break the bond between them.
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Bond length
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It is the distance between the nuclei of two bonded atoms.
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Infrared (IR) spectroscopy
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The technique used to study covalent bonds in molecules.
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electronegativity (EN)
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The ability of a bonded atom attracting the shared electron pair.
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electron affinity (EA)
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The ability of an unbonded atom in gas phase gaining electrons to form a gaseous anion
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Trends in electronegativity (EN)
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EN generally increases up a group and across a period.
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EN and Oxidation number (ON)
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The more EN atom in a bond is assigned all the shared electrons. The less EN atom is assigned none. Each atom in a bond is assigned all of its unshared electrons.
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Oxidation Number (ON)
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O.N. = # of Valence e-s - (# of shared e-s + # of unshared e-s.)
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Polar covalent bond
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When the ENs of atoms are different in a bond, the electrons are shared unequally, and the electron density distribution is unequal.
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Non-polar covalent bond
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When the ENs of atoms are the same in a bond, the electrons are shared equally, and the electron density distribution is equal.
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Electronegativity difference (∆EN)
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It is the difference between the EN values of bonded atoms.
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Partial Ionic Character
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A greater ∆EN results in larger partial charges and a higher partial ionic character.
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∆EN and Ionic character relationship
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∆EN → Ionic character > 1.7 → Mostly ionic 0.4 -1.7 → Polar covalent < 0.4 → Mostly covalent 0 → Nonpolar covalent
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