Chemistry

Front 1

Matter

Back 1

the physical material of the universe

Front 2

elements

Back 2

elementary substances

Front 3

atoms

Back 3

infinitesimally small building blocks of matter

Front 4

molecules

Back 4

combinations of atoms

Front 5

gas

Back 5

no fixed shape or volume

Front 6

liquid

Back 6

distinct volume independent of container but no specific shape

Front 7

solid

Back 7

definite shape and volume; rigid

Front 8

pure substance

Back 8

matter that has a fixed composition and distinct properties

Front 9

elements

Back 9

substances that cannot be decomposed into simpler substances

Front 10

compounds

Back 10

compsed of 2 or more elements

Front 11

mixtures

Back 11

combinations of two or more substances in which each suvstance retains its own chemical identity and hence its own properties

Front 12

law of constant composition (a.k.a. law of definite proportions)

Back 12

The observation that the elemental composition of a pure compound is always the same

Front 13

chemical properties

Back 13

descrive the way a suvstance may change or react to form other substances.

Front 14

intensive properties

Back 14

do not depend on the amount of the sample being examined

Front 15

extensive properties

Back 15

depend on the quantity of the sample and include measurements of mass and volume.

Front 16

physical changes

Back 16

a substance changes its physical appearance but not its composition.

Front 17

chemical changes

Back 17

a substance is transformed into a chemically different substance.

Front 18

Mass

Back 18

a measure of the amount of material in an object

Front 19

Kelvin

Back 19

Celcuis + 273.15

Front 20

Density

Back 20

the amount of mass in a unit volume of a substance. (mass/volume)

Front 21

dimensional analysis

Back 21

aid in problem solving. carry units through all calculations.

Front 22

conversion factor

Back 22

fraction whose numerator and denominator are the same quantity expressed in different untis.

Front 23

Law of Electrostatic Attraction

Back 23

like charges repel one another, unlike charges attract

Front 24

cathode rays

Back 24

radiation that originates from the negative electrode, or cathode

Front 25

radioactivity

Back 25

the spontaneous emission or radiation

Front 26

atomic mass unit (amu)

Back 26

used to measure the masses of atoms

Front 27

angstrom

Back 27

non-SI unit of length usded to express atomic dimensions

Front 28

isotopes

Back 28

atoms of a given element sthat differ in the number of neutrons, and consequently in mass

Front 29

atomic number

Back 29

the number of protons. shown by the subscript

Front 30

mass number

Back 30

the total number of protons plus neutrons in an atom. shown by superscript

Front 31

atomic number

Back 31

the number of protons. shown by the subscript

Front 32

nuclide

Back 32

an atom of a specific isotope

Front 33

mass number

Back 33

total number of protons and neutrons in an atom. shown by the superscript

Front 34

group

Back 34

elements in a column of the periodic table

Front 35

metallic elements

Back 35

all teh elements on the left side and in teh middle of the periodic table (except for hydrogen)

Front 36

nonmetallic elements

Back 36

separated by a diagonal steplike line that fruns from boron to astatine. (includes Hydrogen)

Front 37

metalloids

Back 37

elements that lie along the line that separates metals from nonmetals and have properties that fall between the two

Front 38

molecule

Back 38

an assembly of two or more atoms tightly bound together

Front 39

molecular compounds

Back 39

compounds that are composed of molecules

Front 40

empirical formulas

Back 40

chemical formulas that give only the relative number of atoms of each type in a molecule

Front 41

molecular formulas

Back 41

chemical formulas that indicate the actual numbers and types of atoms in a molecule

Front 42

ion

Back 42

a charged particle formed by removing or adding an electrom to a neutral atom

Front 43

cation

Back 43

ion with a positive charge

Front 44

anion

Back 44

ion with a negative charge

Front 45

polyatomic ions

Back 45

ions that consist of atoms joined as in a molecule, but have a net poitive or negative charge

Front 46

ionic compound

Back 46

a compound that contains positively charged ions and negatively charged ions

Front 47

oxyanions

Back 47

polyatomic anions containing oxygen, having names that end in -ate or -ite

Front 48

oxyanions

Back 48

polyatomic anions containing oxygen, having names that end in -ate or -ite

Front 49

Law of conservation of mass

Back 49

atoms are neither created nor destroyed during any chemical reaction

Front 50

stoichiometry

Back 50

the examination of the quantitative nature of chemical formulas and chemical reactions

Front 51

reactants

Back 51

the chemical formulas on the left of the arrow

Front 52

products

Back 52

the substances produce in the reaction, on the right of the arrow

Front 53

combustion reactions

Back 53

rapid reactions that produce a flame

Front 54

combination reactions

Back 54

two or more substances react to form one product

Front 55

decomposition reaction

Back 55

on substance undergoes a reaction to produce two or more other substances

Front 56

formula weight

Back 56

the sum of the atomic weights of each atom in its chemical formula

Front 57

Avogadro's number

Back 57

6.022E23

Front 58

molar mass

Back 58

the mass in grams of 1 mol of substance. always numerically equal to its formula weight(in amu)

Front 59

limiting reactant/reagent

Back 59

the reactant that is completely consumed in a reaction

Front 60

theoretical yeild

Back 60

the quantity of product that is calculated to form when all of the limiting reactant reacts

Front 61

percent yeild

Back 61

relates the actual yield to the theoretical yield

Front 62

aqueous solutions

Back 62

solutions in which water is the dissolving medium

Front 63

solvent

Back 63

component that is present in greater quantity in a solution

Front 64

solute

Back 64

substance that dissolves in the solvent

Front 65

electrolyte

Back 65

a substance whose aqueous solutions contain ions and conduct electricity

Front 66

nonelectrolyte

Back 66

a substance that does not form ions in solution

Front 67

strong electrolytes

Back 67

Essentially all ionic compounds and a few molecular compounds that exist in solution almost entirely as ions

Front 68

weak electrolytes

Back 68

molecular compounds that produce a small concentration of ions when they dissolve

Front 69

chemical eqiulibrium

Back 69

a state of dynamic balance in which the rate of formation of the products of a reaction from the reactants equals the rate of formation of the reactants from the products

Front 70

precipitation reactions

Back 70

reactions that result in the formatino of an insoluble product

Front 71

precipitate

Back 71

an insoluble solid formed by a reaction in solution

Front 72

solubility

Back 72

the amount of a substance that can be dissolved in a given quantity of solvent

Front 73

exchange/metathesis reactions

Back 73

reactions in which positive ions and negative ions appear to exchange partners

Front 74

molecular equation

Back 74

an equation that shows the complete chemical formulas of the reactants and products

Front 75

complete ionic equation

Back 75

an equation written so that all soluble strong electrolytes shown as ions

Front 76

spectator ions

Back 76

appear in identical forms among both the reactants and products of a complete ionic equation

Front 77

net ionic equation

Back 77

when spectator ions are ommietd from a complete ionic equation

Front 78

acids

Back 78

substances that are able to ionize in aqueous solutions ot form a hydrogen ion and thereby increase the concentration of H+ ions

Front 79

bases

Back 79

substances that accept H+ ions

Front 80

Strong acids and bases

Back 80

acids and bases that are strong electrolytes

acids: HCL, HBr, HI, HClO3, HClO4, HNO3, H2SO4
bases: LiOH, NaOH, KOH, RbOH, CsOH, Ca(OH)2, Sr(OH)2, Ba(OH)2

Front 81

weak acids and bases

Back 81

acids and bases that are weak electrolytes

Front 82

neutralization reaction

Back 82

when a solution of an acid and that of a base are mixed

Front 83

oxidation

Back 83

loss of electrons by a substance

Front 84

reduction

Back 84

gain of electrons by a substance

Front 85

displacement reactions

Back 85

the ion in solution is displaced or replaced through oxidation of an element

Front 86

molarity

Back 86

moles of solute in a liter of solution

Front 87

dilution

Back 87

process of lowering concentrations by addiing water

Front 88

standard solution

Back 88

a second solution of known concentration in a titratino reaction

Front 89

titration

Back 89

using a standard solution that undergoes a specific chmical reaction of known stoichiometry with the solution of unknown concentration.

Front 90

thermodynamics

Back 90

the study of energy and its transformations

Front 91

kinetic energy

Back 91

the energy of motion

Front 92

potential energy

Back 92

"stored" energy that results from teh attractions and repulsions an object experiences in relation to other objects

Front 93

calorie

Back 93

originally defined as teh amount of energy jrequired to raise the temperatuire of 1g of water 1 degree.

Front 94

system

Back 94

the portion of the universe we single out for study

Front 95

surroundings

Back 95

everything not included by the system

Front 96

closed system

Back 96

can exchanged energy but not matter with its surroundings

Front 97

force

Back 97

any push or pull exerted on an object

Front 98

work

Back 98

energy used to cause an object to move against a force

Front 99

heat

Back 99

the energy transfeerred from a hotter object to a colder one

Front 100

energy

Back 100

the capacity to do work or to transfer heat

Front 101

First law of thermodynamics

Back 101

energy can be neither created nor destroyed: energy is conserved

Front 102

internal energy

Back 102

the sum of all the kinetic an potential energy of all the components of the system

Front 103

endothermic

Back 103

when a process occurs in which the system absorbs heat

(heat flows into the system from its surroundings)

Front 104

exothermic

Back 104

a process that results in teh evolution of heat

(heat flows out of hte system and into its surroundings)

Front 105

state function

Back 105

the internal energy of a system

Front 106

enthalpy

Back 106

deals with the heat absorbed or released under constant pressure. a state function

Front 107

enthalpy of reaction

Back 107

the enthalpy change that accompanies a reaction

Front 108

calorimetry

Back 108

the mearurement of heat flow

Front 109

heat capacity

Back 109

the amount of heat required by an object to raise its temperature by 1 K

Front 110

molar heat capacity

Back 110

the heat capacity of 1 mol of a substance

Front 111

specific heat

Back 111

the heat capacity of 1g of a substance

Front 112

bomb calorimeter

Back 112

measures combustion reactions

Front 113

Hess's Law

Back 113

if a reaciton is carried out in a series of steps, delta H for the reaction will be equal to the sum of the enthalpy changes for the individual steps

Front 114

enthalpy of formation

Back 114

the enthalpy change associated with the formation of a compound from its constituent elements

Front 115

standard enthalpy

Back 115

the enthalpy change when all reactants and products are in their standard states.

Front 116

standard enthalpy of formation

Back 116

the change in enthalpy for the reaction that froms 1 mol of the compound from its elements, with all substances in their standard states.

Front 117

fuel value

Back 117

the energy released when 1 g of material is combusted

Front 118

renewable energy

Back 118

energy sources that are essentially inexhaustible

Front 119

electronic structure

Back 119

the arrangement of electrons in an atom

Front 120

electromagnetic radiation

Back 120

carries energy through space and is therefore also known as radiant energy

Front 121

wavelength

Back 121

the distance between successive peaks

Front 122

frequency

Back 122

the number of complete wavelengths, or cycles, that pass a given point in 1 s

Front 123

quantum

Back 123

the smallest quantity of energy that can be emitted or absorbed as electromagnetic radiation

Front 124

photon

Back 124

each energy packet behaves like a tiny particle of light

Front 125

spectrum

Back 125

when radiation from such sources is separated into its different wavelength components

Front 126

continuous spectrum

Back 126

rainbow contianing light of all wavelengths

Front 127

line spectrum

Back 127

a spectrum containig radiation of only specific wavelengths

Front 128

ground state

Back 128

the lowest energy state of an atom

Front 129

excited state

Back 129

when the electron is in a higher energy orbit

Front 130

momentum

Back 130

the quantity mv for any object

Front 131

matter waves

Back 131

the wave characteristics of material particles

Front 132

uncertainty principle

Back 132

the dual nature of matter places a fundamental limitation on how precisely we can know botht hte location and the momentum of any object

Front 133

wave functions

Back 133

a series of mathematical functions from solving schrodinger's equation

Front 134

probaility density

Back 134

the square of the wave function at a agiven point in space represents the probability that the electron will be found at that location

Front 135

orbitals

Back 135

the complete solution to schrodinger's equation for the hydrogen atom yeilding a set of wave functions and corresponding energies.

Front 136

nodes

Back 136

the intermediate regions where the wave function squared goes to zero

Front 137

effective nuclear charge

Back 137

the net positive charge attracting the electron

Front 138

screening effect

Back 138

the inner electrons shielding the outer electron from the full charge of the nucleus

Front 139

degenerate

Back 139

orbitals with the same energy

Front 140

electron spin

Back 140

an intrinsic property of electrons

Front 141

Pauli exclusion principle

Back 141

no two electrons in an atom can have the same set of four quantum numbers

Front 142

Hund's rule

Back 142

for degenerate orbitals, the lowest energy is attained when the number of electrons with the same spin is maximized

Front 143

valence electrons

Back 143

outer-shell electrons

Front 144

core electrons

Back 144

inner-shell electrons

Front 145

transition elements/metals

Back 145

fourth row of the periodic table

Front 146

lanthanide elements

Back 146

the 14 elements corresponding to the filling of the 4f orbitals

Front 147

actinide elements

Back 147

the 5f orbital elements

Front 148

bonding atomic radius

Back 148

an atomic radius, based on teh distances separating atoms when they are chemically bonded to one another

Front 149

ionization energy

Back 149

the minimum energy required to remove an electron from the ground state of the isolated gaseous atom or ion

Front 150

electron affinity

Back 150

the energy change that occurs when an electron is added to a gaseous atom

Front 151

alkali metals

Back 151

group 1A

Front 152

alkaline earth metals

Back 152

group 2A

Front 153

halogens

Back 153

group 7A

Front 154

noble gases

Back 154

group 8A

Front 155

Chemical bond

Back 155

atoms or ions strongly attached to one another

Front 156

ionic bond

Back 156

electrostatic forces that exist between ions of opposite charge

Front 157

covalent bond

Back 157

the sharing of electrons between two atoms

Front 158

metallic bonds

Back 158

found in metals such as copper, iron, and aluminium. each atom is bonded to several neighboring atoms

Front 159

octet rule

Back 159

atoms tend to gain, lose, or share electrons until they are surrounded by eight valence electrons

(exceptions: B[less than] and P[more than])

Front 160

lattice energy

Back 160

the energy required to completely separate a mole of a solid ionic compound into its gaseous ions

Front 161

isoelectronic series

Back 161

the ions possess the same number of electrons

Front 162

single bond

Back 162

sharing of a pair of electrons

Front 163

double bond

Back 163

sharing of 2 electon pairs

Front 164

triple bond

Back 164

sharing of 3 electron pairs. unstable

Front 165

polar covalent bond

Back 165

one of the atoms exerts a greater attraction for the bonding electrons than the other

Front 166

electronegativity

Back 166

the ability of an atome in a molecule to attract electrons to itself

Front 167

polar molecule

Back 167

a molecule in which the centers of positive and negative charge do not coincide

Front 168

dipole

Back 168

whenever two electrical charged of equal magnitude but opposite sign are separated by a distance

Front 169

dipole moment

Back 169

quantitative measure of the magnitude fo a dipole

Front 170

formal charge

Back 170

the charge of an atom in a molecule would have if all atoms had the same electronegativity

Front 171

resonance structures

Back 171

equivalent Lewis structures

Front 172

bond enthalpy

Back 172

the enthalpy change for the breaking of a particular bond in a mole of gaseous substance

(always positive)

Front 173

bond length

Back 173

the distance between the nuclei of the atoms involved in the bond

Front 174

bond angles

Back 174

the angels made by the lines joining the nuclei of the atoms in the molecule

Front 175

VSEPR model

Back 175

valence-shell electron-pair repulsion model

Front 176

electron-domain geometry

Back 176

the arrangement of electron domains about the central atom of a molecule

Front 177

molecular geometry

Back 177

the arrangement of the atoms in space

Front 178

hybrid orbitals

Back 178

orbitals formed by mixing two or more atomic orbitals on an atom

Front 179

sigma bonds

Back 179

a covalent bond in which electron density is concentrated along the internuclear axis

Front 180

pi bond

Back 180

a covalent bond in which electron density is concentrated above and below the line joining the bonded atoms

Front 181

bonding molecular orbital

Back 181

the lower-energy concentrates electron density between the two hydrogen nuclei

Front 182

antibonding molecular orbital

Back 182

the higher MO has very little electron density between the nuclei

Front 183

sigma molecular orbitals

Back 183

a molecular orbital that centers the electron density about an imaginary line passing through two nuclei

Front 184

pi molecular orbitals

Back 184

a molecular orbital that concentrates the electron density on opposite sides of a line that passes through the nuclei

Front 185

paramagnetism

Back 185

the more unpaired electrons in a species, the strongert he force of attraction

Front 186

diamagnetism

Back 186

substances with no unparied electrons are weakly repelled from a magnetic field

Front 187

standard atmospheric pressure

Back 187

the typical pressure at sea level

Front 188

Boyle's law

Back 188

the volume of a fixed quantity of gas maintained at constant temperature is inversely proportional to the pressure

Front 189

Charle's law

Back 189

the volume of a fixed amount of gas maintained at constant pressure is directly proportional to its absolute temperature

Front 190

Avogadro's hypothesis

Back 190

equal volumes of gases at the same temperature and pressure conatin equal numbers of molecules

Front 191

Avogadro's law

Back 191

the volume of a fas maintained at constant temperature and pressure is directly proportional to the number of moles of the gase

Front 192

Dalton's law of partial pressures

Back 192

the total pressure of a mixture of gases equals the sum of hte pressures that each would exert if it were present alone

Front 193

partial pressure

Back 193

the pressure exerted by a particular component of a mixture of gases

Front 194

kinetic-molecular theory

Back 194

1)Gases consist of large numbers of molecules that are in continuous, random motion.
2)The volume of all the molecules of hte gas is negligible compared to the total volume in which the gas is contained.
3)attractive and repulsive forces between gas molecules are ngligible
4)Energy can be transferred between m olecules during collisions, but the average kinetic energy of the molecules does not change with time, as long as the temperature of the gas remains constant.
5)The average kinetic energy of the molecules is proportional to the absolute temperature.

Front 195

effusion

Back 195

the escape of gas molecules through a tiny hole into an evacuated space

Front 196

diffusion

Back 196

the spread of one substance throughout a space or throughout a second substance.

Front 197

mean free path

Back 197

the average distance traveled by a molecule between collisions

Front 198

intermolecular forces

Back 198

the forces that exist between molecules

Front 199

dipole-dipole force

Back 199

exists between neutral polar molecules

Front 200

london dispersion force

Back 200

intermolecular forces resulting from attractions between induced dipoles

Front 201

ion-dipole force

Back 201

exists between an ion and the partial charge on teh end of a polar molecule

Front 202

polarizability

Back 202

the ease with which the charge distribution in amolecule can be distorted by an external electric field

Front 203

hydrogen bonding

Back 203

a special type of intermolecular attraction that exists between the hydrogen atom in a polar bond and an unshared electron pair on a nearby small electronegative ion or atom.

Front 204

viscosity

Back 204

the resistance of liquid to flow

Front 205

surface tension

Back 205

the energy required to increase the surface area of a liquid by a unit amount

Front 206

capillary action

Back 206

the rise of liquids up very narrow tubes

Front 207

heat of fusion

Back 207

the enthalpy change associated wiht melting a solid

Front 208

heat of vaporization

Back 208

the heat needed for the vaporization of a liquid

Front 209

critical temperature

Back 209

the highest temperature at which a substance can exist as a liquid

Front 210

critical pressure

Back 210

the pressure required to bring about liquefaction at this critical temperature

Front 211

dynamic equilibrium

Back 211

the condition in which two opposing processes are occurring simultaneously at equal rates

Front 212

volatile

Back 212

liquids that evaporate readily

Front 213

normal boiling point

Back 213

the boliling point of a liquid at 1 atm of pressure

Front 214

triple point

Back 214

where the three curves intersect on a phase diagram

Front 215

crystalline solid

Back 215

a solid whose atoms, ions, or molecules are ordered in well-defined arrangements

Front 216

amorphous solid

Back 216

a solid whose particles have no orderly structure

Front 217

unti cell

Back 217

the smallest portion of a crystal that reproduces the structure of the entire crystal when repeated in different directions in space.

Front 218

crystal lattice

Back 218

an imaginary network of points on which the repeating unit of the structure of a solid may be imagined to be laid down so that the structure of the crystal is obtained.

Front 219

primitive cubic

Back 219

when lattice points are at the corners only

Front 220

body-centered cubic

Back 220

when a lattice point also occurs at the center of the unit cell

Front 221

face-centered cubic

Back 221

lattice points at the center of each face, as well as at each corner

Front 222

hexagonal close packing

Back 222

if the spheres of the third layer are placed in line with those of the first layer

Front 223

cubic close packing

Back 223

the spheres of the third layer are placed in slightly different positions so that they do not sit above the spheres in teh first layer

Front 224

coordination number

Back 224

the number of particles immediately surrounding a particle in the crystal structure.

Front 225

molecular solids

Back 225

consist of atoms or molecules held together by intermolecular forces

Front 226

covalent-network solids

Back 226

consist of atoms held together in large networks or chains by covalent bonds.

Front 227

ionic solids

Back 227

consist of ions held together by ionic bonds

Front 228

metallic solids

Back 228

consist entirely of metal atoms

Front 229

liquid crystal

Back 229

a substance that exhibits one or more partially ordered liquid phases above the melting point of the solid form.

Front 230

nematic liquid-crystalline phase

Back 230

molecules are aligned along their long axes, but there is no ordering with respect to the ends of the molecules

Front 231

smectic liquid-crystalline phases

Back 231

molecules exhibit additional ordering beyond that of the nematic phase

Front 232

cholesteric liqui-crystalline phase

Back 232

molecules are aligned along their long axes as in nematic liquid crystals but are arranged in layers with the molecules in each plane twiseted slightly in relation to th e moelcules in the planes above and below

Front 233

polymer

Back 233

molecular substances of high moleculer mass formed by the polymerization of monomers

Front 234

monomer

Back 234

molecules with low molecular mass

Front 235

condensatiton polymerization

Back 235

polymerization in which molecules are joinded together through condensation reactions

Front 236

condensatino reaction

Back 236

two molecules are joined to form a larger molecule by elimination of a small molecule such as H2O

Front 237

copolymers

Back 237

polymers formed from two different monomers

Front 238

thermoplastic

Back 238

can be reshaped

Front 239

thermosetting plastic

Back 239

shaped through irreversible chemical processes and therefore cannot be reshaped readily

Front 240

cross-linking

Back 240

forming bonds between chains

Front 241

vulcanization

Back 241

cross-linking of natural rubber

Front 242

biomaterial

Back 242

any material that has a biomedical application

Front 243

cermaics

Back 243

inorganic, nonmetallic, solid materials

Front 244

sol-gel process

Back 244

important method of forming extremely fine particles of uniform size

Front 245

composite

Back 245

complex mixture of two or more materials

Front 246

superconductivity

Back 246

frictionless flow of electrons

Front 247

superconducting transition temperature

Back 247

temperature below which superconductivity may take place

Front 248

vacuum deposition

Back 248

used to form thin films of suvstances that can be vaporized or evaporated without destroying their chemical identities

Front 249

sputtering

Back 249

involves the use of high voltage to remove materila from a source, or target

Front 250

chemical-vapor deposition

Back 250

surface is coasted with a volatile, stable chemical compound at a teperature below the melting point of the surface. then undergoes some form of chemical raction to form a stable, adherent coat.