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33 Cards in this Set
- Front
- Back
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Electronegativity |
a measure of the tendency of an atom in a bond to attract more shared electron density toward itself |
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Chemical bond |
a mutual electrostatic attraction between nuclei and valence electrons of different atoms, that binds the atoms together. atoms form these bonds to lower their potential energy level possible. |
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Ionic bonding |
electrostatic attraction among large numbers ofCATIONS and ANIONS |
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Covalent bonding |
sharing of pairs of valence electrons between two atoms |
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polar covalent bond |
a covalent bond where electrons are shared unequally, so there is a separation of charge. ∆EN must be greater than 0.4. asymmetrical geometry, bond dipoles do not cancel. IMAF is dipole-dipole forces. |
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non polar covalent bond |
electrons are shared equally. ∆EN must be less than 0.4. symmetric geometry, bond dipoles cancel. IMAF is london dispersion forces. |
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ionic compound |
a compound made up of cations and anions |
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formula unit |
a representation of the composition of the compound, showing what elements it is made up of and their relative amounts in the simplest integer ratio. example: CO2 |
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crystal lattice |
a structure of an ionic compound. 3d array with balanced positive and negative charges |
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lattice energy |
energy released when one mole of solid ionic compound is formed from ions in the gas phase. |
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mobile sea of electrons |
valence electrons move around freely while metal ions are fixed in place. explains electrical conductivity, malleability, and luster |
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heat or enthalpy of vaporization |
the amount of energy (enthalpy) that must be added to a liquid substance to transform a quantity of that substance into a gas. the higher the heat of vaporization, the stronger the metallic bond. |
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molecule |
neutral group of atoms, held together by covalent bonds |
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molecular compound |
a compound whose simplest unit is a molecule |
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chemical formula |
a representation of the composition of a compound that specifieswhich elements make it up, and the relative amounts of each |
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molecular formula |
a chemical formula that states exactly how many atoms of each element are in 1 molecule |
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bond length |
distance between nuclei at minimum potential energy |
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bond energy |
energy released when a bond is formed, or energy required to break the bond |
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octet rule |
bonded atoms must have a full valence shell (8 electrons) |
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polyatomic ion |
a charged group of covalently bonded atoms |
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VSEPR theory |
valence shell electron pair repulsion theory. groups of electrons in the valence shell of the central atom repel, and stay as far apart as possible. the repulsion of electron groups determines the shape of the molecule. |
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AB2 molecular geometry |
linear, 180 degrees. |
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AB3 molecular geometry |
trigonal planar, 120 degrees. |
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AB4 molecular geometry |
tetrahedral, 109.5 degrees |
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AB2E molecular geometry |
bent, 120 degrees |
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AB2E2 molecular geometry |
bent, 109.5 degrees |
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AB3E molecular geometry |
trigonal pyramidal, 109.5 degrees |
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AB5 molecular geometry (expanded valence shell) |
trigonal bipyramidal, 120 degrees |
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AB6 molecular geometry (expanded valence shell) |
octahedral, 90 degrees |
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molecular polarity |
when a bond is polar, one atom attracts shared valence electrons more strongly than the other; electrons are shared unequally |
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dipole-dipole forces |
strong, permanent electrostatic attractions between oppositely charged ends of adjacent molecules |
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london dispersion forces |
weak, temporary electrostatic attractions between non-polar molecules, caused by random electron fluctuations. |
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hydrogen bonding |
strong electrostatic attraction between a hydrogen atom bonded to nitrogen, oxygen, or fluorine and an atom with a partial negative charge on an adjacent molecule. |
