Chemical Bonding and Molecular Geometry

Question 1

Ionic Bonds

Answer 1

Strong electrostatic force of attraction between cations and anions in an ionic compound

Question 2

Inert Pair Effect

Answer 2

Tendency of heavy atoms to form ions in which their valence s electrons are not lost

Question 3

Covalent Bonds

Answer 3

Bond formed when electrons are shared between atoms

Question 4

Bond Length

Answer 4

Distance between the nuclei of two bonded atoms at which the lowest potential energy is achieved

Question 5

Pure Covalent Bond (Nonpolar Covalent Bond)

Answer 5

Covalent bond between atoms of identical electronegativities

Question 6

Polar Covalent Bond

Answer 6

Covalent bond between atoms of different electronegativities; a covalent bond with a positive end and a negative end

Question 7

Electronegativity

Answer 7

Tendency of an atom to attract electrons in a bond to itself

Question 8

Lewis Symbol

Answer 8

Symbol for an element or monatomic ion that uses a dot to represent each valence electron in the element or ion

Question 9

Lewis Structures

Answer 9

Diagram showing lone pairs and bonding pairs of electrons in a molecule or an ion

Question 10

Lone Pairs

Answer 10

Two (a pair of) valence electrons that are not used to form a covalent bond

Question 11

Single Bond

Answer 11

Bond in which a single pair of electrons in shared between two atoms

Question 12

Octet Rule

Answer 12

Guideline that states main group atoms will form structures in which eight valence electrons interact with each nucleus, counting bonding electrons as interacting with both atoms connected by the bond

Question 13

Double Bond

Answer 13

Covalent bond in which two pairs of electrons are shared between two atoms

Question 14

Triple Bond

Answer 14

Bond in which three pairs of electrons are shared between two atoms

Question 15

Free Radicals

Answer 15

Molecule that contains an odd number of electrons

Question 16

Hypervalent Molecules

Answer 16

Molecule containing at least one main group element that has more than eight electrons in its valence shell

Question 17

Formal Charge

Answer 17

Charge that would result on an atom by taking the number of valence electrons on the neutral atom and subtracting the nonbonding electrons and the number of bonds (one-half of the bonding electrons)

Question 18

Molecular Structure

Answer 18

Arrangement of atoms in a molecule or ion or structure that includes only the placement of the atoms in the molecule

Question 19

Resonance

Answer 19

Situation in which one Lewis structure is insufficient to describe the bonding in a molecule and the average of multiple structures is observed

Question 20

Resonance Forms

Answer 20

Two or more Lewis structures that have the same arrangement of atoms but different arrangements of electrons

Question 21

Resonance Hybrid

Answer 21

Average of the resonance forms shown by the individual Lewis structures

Question 22

Bond Energy (Bond Dissociation Energy)

Answer 22

Energy required to break a covalent bond in a gaseous substance

Question 23

Lattice Energy (delta H sub lattice)

Answer 23

Energy required to separate one mole of an ionic solid into its component gaseous ions

Question 24

Bond Angle

Answer 24

Angle between any two covalent bonds that share a common atom

Question 25

Born-Haber Cycle

Answer 25

Thermochemical cycle relating the various energetic steps involved in the formation of an ionic solid from the relevant elements

Question 26

Valence Shell Electron-Pair Repulsion Theory (VSEPR Theory)

Answer 26

Theory used to predict the bond angles in a molecule based on positioning regions of high electron density as far apart as possible to minimize electrostatic repulsion

Question 27

Linear

Answer 27

Shape in which two outside groups are placed on opposite sides of a central atom

Question 28

Trigonal Planar

Answer 28

Shape in which three outside groups are placed in a flat triangle around a central atom with 120* angles between each pair and the central atom

Question 29

Tetrahedral

Answer 29

Shape in which four outside groups are placed around a central atom such that a three-dimensional shape is generated with four corners and 109.5* angles between each pair and the central atom

Question 30

Trigonal Bipyramidal

Answer 30

Shape in which five outside groups are placed around a central atom such that three form a flat triangle with 120* angles between each pair and the central atom, and the other two form the apex of two pyramids, one above and one below the triangular plane

Question 31

Octahedral

Answer 31

Shape in which six outside groups are placed around a central atom such that a three-dimensional shape is generated with four groups forming a square and the other two forming the apex of two pyramids, one above and one below the square plane

Question 32

Electron-Pair Geometry

Answer 32

Arrangement around a central atom of all regions of electron density (bonds, lone pairs, or unpaired electrons)

Question 33

Axial Position

Answer 33

Location in a trigonal bipyramidal geometry in which there is another atom at a 180* angle and the equatorial positions are at a 90* angle

Question 34

Equatorial Position

Answer 34

One of the three positions in a trigonal bipyramidal geometry with 120* angles between them; the axial positions are located at a 90* angle

Question 35

Bond Dipole Moment

Answer 35

Separation of charge in a bond that depends on the difference in electronegativity and the bond distance represented by partial charges or a vector

Question 36

Vector

Answer 36

Quantity having magnitude and direction

Question 37

Polar Molecule (Dipole)

Answer 37

Molecule with an overall dipole moment

Question 38

Dipole Moment

Answer 38

Property of a molecule that describes the separation of charge determined by the sum of the individual bond moments based on the molecular structure