Are atoms more likely to be found as independent particles, or combinations of atoms?
Combinations of Atoms
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a mutual electrical attraction between the nuclei and valence electrons of different atoms that binds the atoms together
Chemical Bond
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Atoms form \______________ by gaining, losing, or sharing electrons.
Compounds
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A measure of the ability of an atom in a chemical compound to attract electrons in a chemical bond
Electronegativity
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3\.3 to 1.7, %100-50
Ionic
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Unequal sharing of electrons, 1.7 to .3, %50-5
Polar Covalent
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Equal sharing of electrons, .3 to 0, %5-0
Nonpolar Covalent
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δ-, for the element in a compound with a greater electronegativity in a polar bond
Slightly Negative Symbol
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δ+, for the element in a compound with a smaller electronegativity in a polar bond
Slightly Positive Symbol
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A chemical compound whose simplest units are molecules
Molecular Compounds
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A molecule is still neutral when polar because the \______________ positives and negatives cancel each other out
Slight
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Atoms tend to form bonds to follow the \____________ rule
Octet
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atoms gain, lose, or share valence electrons to achieve noble gas configuration
Octet Rule
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Hydrogen is an exception to the octet rule because hydrogen forms bonds when it is surrounded by only \________ electrons
Two
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BF3 is an exception because boron has __ valence electrons an receives an electron from each of the three fluorine atoms for a total of __ electrons
3, 6
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what are the Expanded Octets
PCl5 and SF6
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an electron configuration in which only the valence electrons of an atom of a particular element are shown, indicated by dots placed around the element's symbol
Electron Dot Notation
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Electron dot notations can represent \_____________
Compounds
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A pair of valance electrons that is not shared between atoms
Lone Paired Electrons
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Formulas in which dot-pairs or dashes between two atomic symbols represent electron pairs in covalent bonds, and dots adjacent to only one atomic symbol represent unshared electrons, with no unpaired electrons
Lewis Structures
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atoms gain, lose, or share electrons to achieve what
greater stability, noble gas configuration, and an octet in the outer energy level
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what is a neutral group of atoms held together by covalent bonds
molecule
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the types and numbers of atoms joined in a single molecule of a molecular compound is termed what
molecular formula
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ionic bonds form as a result of the attraction between what
anions and cations
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you can classify a bond by calculating
the difference in the atoms’ electronegativities
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the greater the difference in electronegativity between two atoms, the great the %\_____
ionic
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if two covalently bonded atoms are identical, the bond is
non-polar covalent
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in a molecule of Hal, which atom would be slightly positive
hydrogen
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which type of bond would be described as unequal sharing of electron pairs between atoms
polar covalent
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what is composed of positive and negative ions that are combined so that the numbers of positive and negative charges are equal
Ionic compound
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what is different between ionic compounds and molecular compound
an ionic compound is not composed of independent, nuetral units that cam be isolated and examined, while molecular compounds are
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which has a stronger attraction between formula units and molecules and why
formula units’ attractions are stronger than molecules’ due to the molecule's’ hydrogen bonds
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between ions and molecules which are solid and gas at room temp
ions are solids and molecules are gases at room temp
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between ionic and molecular compounds which melt at low temps and which at high temps
molecular compounds melt at low temps while ionic compounds have higher melting points
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when can ionic compounds conduct electricity
when they are in the molten state because they can move freely to carry electrical currents
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what is a polyatomic ion
it is a charged group of covalently bonded atoms why
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why are ionic compounds hard but brittle
forces in ions crystals make it difficult for one layer to move relative to another. Where one layer moves, the repulsive forces make the layers part completely, causing them to be brittle
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do polyatomic bond covalently or ionically
ionically
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what is the therm for the force that holds two ions together in an ionic bond
electrostatic force
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what is the smallest of the ions in an ionic compound from which its chemical formula can be written
formula unit
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what is unequal sharing of electron pairs which results in uneven distribution of charge