Chapter 2

Question 1

Temporary Dipole

Answer 1

Formed when the electrons, which are constantly in motion, are momentarily arranged so as to produce an asymmetric charge distribution.

Question 2

Hydrogen Bond

Answer 2

Occurs whenever a hydrogen atom can be shared between two strongly electronegative atoms such as N, O, F, or Cl.

Question 3

Coordination Number

Answer 3

The arrangement of atoms within a solid can be principally characterized by the number of nearest neighbors

Question 4

Core Electrons

Answer 4

The electrons in the filled shells “below” the valence shell.

Question 5

Metallic Bonds

Answer 5

Solids composed primarily of electropositive elements containing three or fewer valence electrons are bonded by metallic Bonds

Question 6

amorphous material

Answer 6

A type of solid that only exhibits short-range order

Question 7

Arrhenius equation

Answer 7

Reaction rate = C^(-Q/RT) ; where Q is the activation energy, T is absolute gas temperature, R is the gas constant.

Question 8

atomic scale structure

Answer 8

1. The types of atoms present
2. The types of bonding between the atoms
3. the way the atoms are packed together

Question 9

bond angles

Answer 9

angles between atoms or molecules that are bonded.

Question 10

bond energy

Answer 10

measure of the inherent strength of a bond

Question 11

bond-energy curve

Answer 11

An illustration of the relationship between U and x and is sometimes called the bond energy well

Question 12

bond-force curve

Answer 12

illustration showing the relationship between competing forces and x

Question 13

bond length

Answer 13

average center-to-center distance between atoms

Question 14

coefficient of thermal expansion

Answer 14

Macroscopic property with connection to the bond-energy curve. As temp increases atoms are able to move up the sides of the energy well.

Question 15

covalent bonds

Answer 15

Form in compounds composed of electronegative elements, especially those with four or more valence electrons.

Question 16

crosslinks

Answer 16

The primary bonds between rubber chains formed by the opening of the unsaturated double bonds

Question 17

crystalline materials

Answer 17

A type of solid that exhibits both short-range order and long-range order

Question 18

ductile

Answer 18

Atoms in a material can slip past one another after impact.

Question 19

electron affinity

Answer 19

The energy released when an isolated neutral electronegative atom gains an electron.

Question 20

electron configuration

Answer 20

the distribution of electrons within the permissible energy levels

Question 21

electronegativity

Answer 21

The relative tendency of that element to gain, or attract, an electron, generally increases as you read the periodic table from left to right.

Question 22

short-range order

Answer 22

the number and type of nearest neighbors associated with a particular solid structure

Question 23

Young’s modulus (E)

Answer 23

A measure of the resistance of the material to relative atomic separation (stiffness).

Question 24

ground state

Answer 24

electrons occupy the lowest energy subshells consistent with the pauli exclusion principle

Question 25

ionic bond

Answer 25

Bond in a compound containing both electropositive and electronegative elements. This bond involves electron transfer from the electropositve atom to the electronegitive one.

Question 26

ionization potential

Answer 26

The energy required to remove an electron from an isolated neutral atom

Question 27

intermetallics

Answer 27

materials made of a mix of metals that usually exhibit either mixed metallic/covalent or mixed metallic/ionic bonds characteristics.

Question 28

Pauli exclusion principle

Answer 28

states that no two interacting electrons may have the same four quantum numbers.

Question 29

polymers

Answer 29

many identical units(mers) linked together

Question 30

quantum number

Answer 30

Valid solutions to the schrodinger equation identified by a set of three integer values (n, l, and m).

Question 31

thermodynamics

Answer 31

The study of the relationships between the thermal properties of matter and external variables such as pressure, temperature, and composition

Question 32

thermoplastic polymer

Answer 32

linear polymers that form melts upon heating

Question 33

thermoset polymer

Answer 33

polymers that do not form a melt

Question 34

valence electrons

Answer 34

electrons on the outer most shell of an atom