{"id":3289,"date":"2020-08-19T17:13:41","date_gmt":"2020-08-19T21:13:41","guid":{"rendered":"https:\/\/pressbooks.bccampus.ca\/inorganicchemistrychem250\/?post_type=back-matter&p=3289"},"modified":"2020-08-19T17:13:41","modified_gmt":"2020-08-19T21:13:41","slug":"glossary","status":"publish","type":"back-matter","link":"https:\/\/pressbooks.bccampus.ca\/inorganicchemistrychem250\/back-matter\/glossary\/","title":{"raw":"Glossary","rendered":"Glossary"},"content":{"raw":"","rendered":"
\n
\u03c0 bonding orbital<\/dfn><\/dt>\n
\n

molecular orbital formed by side-by-side overlap of atomic orbitals, in which the electron density is found on opposite sides of the internuclear axis<\/p>\n<\/dd>\n

\u03c3 bonding orbital<\/dfn><\/dt>\n
\n

molecular orbital in which the electron density is found along the axis of the bond<\/p>\n<\/dd>\n

\u03c0* bonding orbital<\/dfn><\/dt>\n
\n

antibonding molecular orbital formed by out of phase side-by-side overlap of atomic orbitals, in which the electron density is found on both sides of the internuclear axis, and there is a node between the nuclei<\/p>\n<\/dd>\n

\u03c3* bonding orbital<\/dfn><\/dt>\n
\n

antibonding molecular orbital formed by out-of-phase overlap of atomic orbital along the axis of the bond, generating a node between the nuclei<\/p>\n<\/dd>\n

acid anhydride<\/dfn><\/dt>\n
\n

compound that reacts with water to form an acid or acidic solution<\/p>\n<\/dd>\n

acid ionization<\/dfn><\/dt>\n
\n

reaction involving the transfer of a proton from an acid to water, yielding hydronium ions and the conjugate base of the acid<\/p>\n<\/dd>\n

acid ionization constant (Ka)<\/dfn><\/dt>\n
\n

equilibrium constant for an acid ionization reaction<\/p>\n<\/dd>\n

acid-base indicator<\/dfn><\/dt>\n
\n

weak acid or base whose conjugate partner imparts a different solution color; used in visual assessments of solution pH<\/p>\n<\/dd>\n

acidic<\/dfn><\/dt>\n
\n

a solution in which [H3O+] > [OH\u2212]<\/p>\n<\/dd>\n

actinide<\/dfn><\/dt>\n
\n

inner transition metal in the bottom of the bottom two rows of the periodic table<\/p>\n<\/dd>\n

actinide series<\/dfn><\/dt>\n
\n

(also, actinoid series) actinium and the elements in the second row or the f-block, atomic numbers 89\u2013103<\/p>\n<\/dd>\n

active electrode<\/dfn><\/dt>\n
\n

electrode that participates as a reactant or product in the oxidation-reduction reaction of an electrochemical cell; the mass of an active electrode changes during the oxidation-reduction reaction<\/p>\n<\/dd>\n

alkali metal<\/dfn><\/dt>\n
\n

element in group 1<\/p>\n<\/dd>\n

alkaline battery<\/dfn><\/dt>\n
\n

primary battery similar to a dry cell that uses an alkaline (often potassium hydroxide) electrolyte; designed to be an improved replacement for the dry cell, but with more energy storage and less electrolyte leakage than typical dry cell<\/p>\n<\/dd>\n

alkaline earth metal<\/dfn><\/dt>\n
\n

element in group 2<\/p>\n<\/dd>\n

allotropes<\/dfn><\/dt>\n
\n

two or more forms of the same element, in the same physical state, with different chemical structures<\/p>\n<\/dd>\n

amorphous<\/dfn><\/dt>\n
\n

solid material such as a glass that does not have a regular repeating component to its three-dimensional structure; a solid but not a crystal<\/p>\n<\/dd>\n

amphiprotic<\/dfn><\/dt>\n
\n

species that may either donate or accept a proton in a Bronsted-Lowry acid-base reaction<\/p>\n<\/dd>\n

amphoteric<\/dfn><\/dt>\n
\n

species that can act as either an acid or a base<\/p>\n<\/dd>\n

anode<\/dfn><\/dt>\n
\n

electrode in an electrochemical cell at which oxidation occurs<\/p>\n<\/dd>\n

antibonding orbital<\/dfn><\/dt>\n
\n

molecular orbital located outside of the region between two nuclei; electrons in an antibonding orbital destabilize the molecule<\/p>\n<\/dd>\n

aqueous solution<\/dfn><\/dt>\n
\n

solution for which water is the solvent<\/p>\n<\/dd>\n

Aufbau principle<\/dfn><\/dt>\n
\n

procedure in which the electron configuration of the elements is determined by \u201cbuilding\u201d them in order of atomic numbers, adding one proton to the nucleus and one electron to the proper subshell at a time<\/p>\n<\/dd>\n

autoionization<\/dfn><\/dt>\n
\n

reaction between identical species yielding ionic products; for water, this reaction involves transfer of protons to yield hydronium and hydroxide ions<\/p>\n<\/dd>\n

axial position<\/dfn><\/dt>\n
\n

location in a trigonal bipyramidal geometry in which there is another atom at a 180\u00b0 angle and the equatorial positions are at a 90\u00b0 angle<\/p>\n<\/dd>\n

base anhydride<\/dfn><\/dt>\n
\n

metal oxide that behaves as a base towards acids<\/p>\n<\/dd>\n

base ionization<\/dfn><\/dt>\n
\n

reaction involving the transfer of a proton from water to a base, yielding hydroxide ions and the conjugate acid of the base<\/p>\n<\/dd>\n

base ionization constant (Kb)<\/dfn><\/dt>\n
\n

equilibrium constant for a base ionization reaction<\/p>\n<\/dd>\n

basic<\/dfn><\/dt>\n
\n

a solution in which [H3O+] < [OH\u2212]<\/p>\n<\/dd>\n

battery<\/dfn><\/dt>\n
\n

single or series of galvanic cells designed for use as a source of electrical power<\/p>\n<\/dd>\n

bicarbonate anion<\/dfn><\/dt>\n
\n

salt of the hydrogen carbonate ion HCO3-<\/p>\n<\/dd>\n

bidentate ligand<\/dfn><\/dt>\n
\n

ligand that coordinates to one central metal through coordinate bonds from two different atoms<\/p>\n<\/dd>\n

binary acid<\/dfn><\/dt>\n
\n

compound that contains hydrogen and one other element, bonded in a way that imparts acidic properties to the compound (ability to release H+ ions when dissolved in water)<\/p>\n<\/dd>\n

binary compound<\/dfn><\/dt>\n
\n

compound containing two different elements.<\/p>\n<\/dd>\n

bismuth<\/dfn><\/dt>\n
\n

heaviest member of group 15; a less reactive metal than other representative metals<\/p>\n<\/dd>\n

bond angle<\/dfn><\/dt>\n
\n

angle between any two covalent bonds that share a common atom<\/p>\n<\/dd>\n

bond dipole moment<\/dfn><\/dt>\n
\n

separation of charge in a bond that depends on the difference in electronegativity and the bond distance represented by partial charges or a vector<\/p>\n<\/dd>\n

bond distance<\/dfn><\/dt>\n
\n

(also, bond length) distance between the nuclei of two bonded atoms<\/p>\n<\/dd>\n

bond energy<\/dfn><\/dt>\n
\n

(also, bond dissociation energy) energy required to break a covalent bond in a gaseous substance<\/p>\n<\/dd>\n

bond length<\/dfn><\/dt>\n
\n

distance between the nuclei of two bonded atoms at which the lowest potential energy is achieved<\/p>\n<\/dd>\n

bond order<\/dfn><\/dt>\n
\n

number of pairs of electrons between two atoms; it can be found by the number of bonds in a Lewis structure or by the difference between the number of bonding and antibonding electrons divided by two<\/p>\n<\/dd>\n

bonding orbital<\/dfn><\/dt>\n
\n

molecular orbital located between two nuclei; electrons in a bonding orbital stabilize a molecule<\/p>\n<\/dd>\n

borate<\/dfn><\/dt>\n
\n

compound containing boron-oxygen bonds, typically with clusters or chains as a part of the chemical structure<\/p>\n<\/dd>\n

Born-Haber cycle<\/dfn><\/dt>\n
\n

thermochemical cycle relating the various energetic steps involved in the formation of an ionic solid from the relevant elements<\/p>\n<\/dd>\n

Br\u00f8nsted-Lowry acid<\/dfn><\/dt>\n
\n

proton donor<\/p>\n<\/dd>\n

Br\u00f8nsted-Lowry base<\/dfn><\/dt>\n
\n

proton acceptor<\/p>\n<\/dd>\n

buffer<\/dfn><\/dt>\n
\n

mixture of appreciable amounts of a weak acid-base pair the pH of a buffer resists change when small amounts of acid or base are added<\/p>\n<\/dd>\n

buffer capacity<\/dfn><\/dt>\n
\n

amount of an acid or base that can be added to a volume of a buffer solution before its pH changes significantly (usually by one pH unit)<\/p>\n<\/dd>\n

carbonate<\/dfn><\/dt>\n
\n

salt of the anion CO_3^2- often formed by the reaction of carbon dioxide with bases<\/p>\n<\/dd>\n

cathode<\/dfn><\/dt>\n
\n

electrode in an electrochemical cell at which reduction occurs<\/p>\n<\/dd>\n

cathodic protection<\/dfn><\/dt>\n
\n

approach to preventing corrosion of a metal object by connecting it to a sacrificial anode composed of a more readily oxidized metal<\/p>\n<\/dd>\n

cell notation (schematic)<\/dfn><\/dt>\n
\n

symbolic representation of the components and reactions in an electrochemical cell<\/p>\n<\/dd>\n

cell potential<\/dfn><\/dt>\n
\n

difference in potential of the cathode and anode half-cells<\/p>\n<\/dd>\n

central metal<\/dfn><\/dt>\n
\n

ion or atom to which one or more ligands is attached through coordinate covalent bonds<\/p>\n<\/dd>\n

chalcogen<\/dfn><\/dt>\n
\n

element in group 16<\/p>\n<\/dd>\n

chelate<\/dfn><\/dt>\n
\n

complex formed from a polydentate ligand attached to a central metal<\/p>\n<\/dd>\n

chelating ligand<\/dfn><\/dt>\n
\n

ligand that attaches to a central metal ion by bonds from two or more donor atoms<\/p>\n<\/dd>\n

chemical reduction<\/dfn><\/dt>\n
\n

method of preparing a representative metal using a reducing agent<\/p>\n<\/dd>\n

chemistry<\/dfn><\/dt>\n
\n

study of the composition, properties, and interactions of matter<\/p>\n<\/dd>\n

chlor-alkali process<\/dfn><\/dt>\n
\n

electrolysis process for the synthesis of chlorine and sodium hydroxide<\/p>\n<\/dd>\n

cis configuration<\/dfn><\/dt>\n
\n

configuration of a geometrical isomer in which two similar groups are on the same side of an imaginary reference line on the molecule<\/p>\n<\/dd>\n

color-change interval<\/dfn><\/dt>\n
\n

range in pH over which the color change of an indicator is observed<\/p>\n<\/dd>\n

common ion effect<\/dfn><\/dt>\n
\n

effect on equilibrium when a substance with an ion in common with the dissolved species is added to the solution; causes a decrease in the solubility of an ionic species, or a decrease in the ionization of a weak acid or base<\/p>\n<\/dd>\n

complex ion<\/dfn><\/dt>\n
\n

ion consisting of a central atom surrounding molecules or ions called ligands via coordinate covalent bonds<\/p>\n<\/dd>\n

concentrated<\/dfn><\/dt>\n
\n

qualitative term for a solution containing solute at a relatively high concentration<\/p>\n<\/dd>\n

concentration<\/dfn><\/dt>\n
\n

quantitative measure of the relative amounts of solute and solvent present in a solution<\/p>\n<\/dd>\n

concentration cell<\/dfn><\/dt>\n
\n

galvanic cell comprising half-cells of identical composition but for the concentration of one redox reactant or product<\/p>\n<\/dd>\n

conjugate acid<\/dfn><\/dt>\n
\n

substance formed when a base gains a proton<\/p>\n<\/dd>\n

conjugate base<\/dfn><\/dt>\n
\n

substance formed when an acid loses a proton<\/p>\n<\/dd>\n

coordinate covalent bond<\/dfn><\/dt>\n
\n

(also, dative bond) covalent bond in which both electrons originated from the same atom<\/p>\n<\/dd>\n

coordination compound<\/dfn><\/dt>\n
\n

stable compound in which the central metal atom or ion acts as a Lewis acid and accepts one or more pairs of electrons<\/p>\n<\/dd>\n

coordination number<\/dfn><\/dt>\n
\n

number of coordinate covalent bonds to the central metal atom in a complex or the number of closest contacts to an atom in a crystalline form<\/p>\n<\/dd>\n

coordination sphere<\/dfn><\/dt>\n
\n

central metal atom or ion plus the attached ligands of a complex<\/p>\n<\/dd>\n

core electron<\/dfn><\/dt>\n
\n

electron in an atom that occupies the orbitals of the inner shells<\/p>\n<\/dd>\n

corrosion<\/dfn><\/dt>\n
\n

degradation of metal via a natural electrochemical process<\/p>\n<\/dd>\n

coupled equilibria<\/dfn><\/dt>\n
\n

system characterized the simultaneous establishment of two or more equilibrium reactions sharing one or more reactant or product<\/p>\n<\/dd>\n

covalent bond<\/dfn><\/dt>\n
\n

attractive force between the nuclei of a molecule\u2019s atoms and pairs of electrons between the atoms<\/p>\n<\/dd>\n

covalent radius<\/dfn><\/dt>\n
\n

one-half the distance between the nuclei of two identical atoms when they are joined by a covalent bond<\/p>\n<\/dd>\n

crystal field splitting<\/dfn><\/dt>\n
\n

difference in energy between the t2g and eg sets or t and e sets of orbitals<\/p>\n<\/dd>\n

crystal field theory<\/dfn><\/dt>\n
\n

model that explains the energies of the orbitals in transition metals in terms of electrostatic interactions with the ligands but does not include metal ligand bonding<\/p>\n<\/dd>\n

d-block element<\/dfn><\/dt>\n
\n

one of the elements coordination compound groups 3\u201311 with valence electrons in d orbitals<\/p>\n<\/dd>\n

degenerate orbitals<\/dfn><\/dt>\n
\n

orbitals that have the same energy<\/p>\n<\/dd>\n

diamagnetism<\/dfn><\/dt>\n
\n

phenomenon in which a material is not magnetic itself but is repelled by a magnetic field; it occurs when there are only paired electrons present<\/p>\n<\/dd>\n

dilute<\/dfn><\/dt>\n
\n

qualitative term for a solution containing solute at a relatively low concentration<\/p>\n<\/dd>\n

dilution<\/dfn><\/dt>\n
\n

process of adding solvent to a solution in order to lower the concentration of solutes<\/p>\n<\/dd>\n

dipole moment<\/dfn><\/dt>\n
\n

property of a molecule that describes the separation of charge determined by the sum of the individual bond moments based on the molecular structure<\/p>\n<\/dd>\n

diprotic acid<\/dfn><\/dt>\n
\n

acid containing two ionizable hydrogen atoms per molecule<\/p>\n<\/dd>\n

diprotic base<\/dfn><\/dt>\n
\n

base capable of accepting two protons<\/p>\n<\/dd>\n

disproportionation reaction<\/dfn><\/dt>\n
\n

chemical reaction where a single reactant is simultaneously reduced and oxidized; it is both the reducing agent and the oxidizing agent<\/p>\n<\/dd>\n

dissociation constant (Kd)<\/dfn><\/dt>\n
\n

equilibrium constant for the decomposition of a complex ion into its components<\/p>\n<\/dd>\n

dissolved<\/dfn><\/dt>\n
\n

describes the process by which solute components are dispersed in a solvent<\/p>\n<\/dd>\n

donor atom<\/dfn><\/dt>\n
\n

atom in a ligand with a lone pair of electrons that forms a coordinate covalent bond to a central metal<\/p>\n<\/dd>\n

Downs cell<\/dfn><\/dt>\n
\n

electrochemical cell used for the commercial preparation of metallic sodium (and chlorine) from molten sodium chloride<\/p>\n<\/dd>\n

dry cell<\/dfn><\/dt>\n
\n

primary battery, also called a zinc-carbon battery, based on the spontaneous oxidation of zinc by manganese(IV)<\/p>\n<\/dd>\n

e_g orbitals<\/dfn><\/dt>\n
\n

set of two d orbitals that are oriented on the Cartesian axes for coordination complexes; in octahedral complexes, they are higher in energy than the t2g orbitals<\/p>\n<\/dd>\n

effective nuclear charge<\/dfn><\/dt>\n
\n

charge that leads to the Coulomb force exerted by the nucleus on an electron, calculated as the nuclear charge minus shielding<\/p>\n<\/dd>\n

electrode potential<\/dfn><\/dt>\n
\n

the potential of a cell in which the half-cell of interest acts as a cathode when connected to the standard hydrogen electrode<\/p>\n<\/dd>\n

electrolysis<\/dfn><\/dt>\n
\n

process using electrical energy to cause a nonspontaneous process to occur<\/p>\n<\/dd>\n

electrolytic cell<\/dfn><\/dt>\n
\n

electrochemical cell in which an external source of electrical electrolysis power is used to drive an otherwise nonspontaneous process<\/p>\n<\/dd>\n

electron affinity<\/dfn><\/dt>\n
\n

energy change associated with addition of an electron to a gaseous atom or ion<\/p>\n<\/dd>\n

electron configuration<\/dfn><\/dt>\n
\n

listing that identifies the electron occupancy of an atom\u2019s shells and subshells<\/p>\n<\/dd>\n

electron-pair geometry<\/dfn><\/dt>\n
\n

arrangement around a central atom of all regions of electron density (bonds, lone pairs, or unpaired electrons)<\/p>\n<\/dd>\n

electronegativity<\/dfn><\/dt>\n
\n

tendency of an atom to attract electrons in a bond to itself<\/p>\n<\/dd>\n

entropy (S)<\/dfn><\/dt>\n
\n

state function that is a measure of the matter and\/or energy dispersal within a system, determined by the number of system microstates; often described as a measure of the disorder of the system<\/p>\n<\/dd>\n

equatorial position<\/dfn><\/dt>\n
\n

one of the three positions in a trigonal bipyramidal geometry with 120\u00b0 angles between them; the axial positions are located at a 90\u00b0 angle<\/p>\n<\/dd>\n

equilibrium<\/dfn><\/dt>\n
\n

state of a reversible reaction in which the forward and reverse processes occur at equal rates<\/p>\n<\/dd>\n

equilibrium constant (K)<\/dfn><\/dt>\n
\n

value of the reaction quotient for a system at equilibrium; may be expressed using concentrations (Kc) or partial pressures (Kp)<\/p>\n<\/dd>\n

f-block element<\/dfn><\/dt>\n
\n

(also, inner transition element) one of the elements with atomic numbers 58\u201371 or 90\u2013103 that have valence electrons in f orbitals; they are frequently shown offset below the periodic table<\/p>\n<\/dd>\n

Faraday\u2019s constant (F)<\/dfn><\/dt>\n
\n

charge on 1 mol of electrons; F = 96,485 C\/mol e\u2212<\/p>\n<\/dd>\n

first transition series<\/dfn><\/dt>\n
\n

transition elements in the fourth period of the periodic table (first row of the d-block), atomic numbers 21\u201329<\/p>\n<\/dd>\n

formation constant (Kf)<\/dfn><\/dt>\n
\n

(also, stability constant) equilibrium constant for the formation of a complex ion from its components<\/p>\n<\/dd>\n

fourth transition series<\/dfn><\/dt>\n
\n

transition elements in the seventh period of the periodic table (fourth row of the d-block), atomic numbers 89 and 104\u2013111<\/p>\n<\/dd>\n

Frasch process<\/dfn><\/dt>\n
\n

important in the mining of free sulfur from enormous underground deposits<\/p>\n<\/dd>\n

fuel cell<\/dfn><\/dt>\n
\n

devices similar to galvanic cells that require a continuous feed of redox reactants; also called a flow battery<\/p>\n<\/dd>\n

galvanic (voltaic) cell<\/dfn><\/dt>\n
\n

electrochemical cell in which a spontaneous redox reaction takes place; also called a voltaic cell<\/p>\n<\/dd>\n

galvanization<\/dfn><\/dt>\n
\n

method of protecting iron or similar metals from corrosion by coating with a thin layer of more easily oxidized zinc.<\/p>\n<\/dd>\n

geometric isomers<\/dfn><\/dt>\n
\n

isomers that differ in the way in which atoms are oriented in space relative to each other, leading to different physical and chemical properties<\/p>\n<\/dd>\n

Gibbs free energy change (G)<\/dfn><\/dt>\n
\n

thermodynamic property defined in terms of system enthalpy and entropy; all spontaneous processes involve a decrease in G<\/p>\n<\/dd>\n

group<\/dfn><\/dt>\n
\n

vertical column of the periodic table<\/p>\n<\/dd>\n

Haber process<\/dfn><\/dt>\n
\n

main industrial process used to produce ammonia from nitrogen and hydrogen; involves the use of an iron catalyst and elevated temperatures and pressures<\/p>\n<\/dd>\n

half cell<\/dfn><\/dt>\n
\n

component of a cell that contains the redox conjugate pair (\u201ccouple\u201d) of a single reactant<\/p>\n<\/dd>\n

halide<\/dfn><\/dt>\n
\n

compound containing an anion of a group 17 element in the 1\u2212 oxidation state (fluoride, F\u2212; chloride, Cl\u2212; bromide, Br\u2212; and iodide, I\u2212)<\/p>\n<\/dd>\n

Hall\u2013H\u00e9roult cell<\/dfn><\/dt>\n
\n

electrolysis apparatus used to isolate pure aluminum metal from a solution of alumina in molten cryolite<\/p>\n<\/dd>\n

halogen<\/dfn><\/dt>\n
\n

element in group 17<\/p>\n<\/dd>\n

Henderson-Hasselbalch equation<\/dfn><\/dt>\n
\n

logarithmic version of the acid ionization constant expression, conveniently formatted for calculating the pH of buffer solutions<\/p>\n<\/dd>\n

heterogeneous catalyst<\/dfn><\/dt>\n
\n

catalyst present in a different phase from the reactants, furnishing a surface at which a reaction can occur<\/p>\n<\/dd>\n

heterogeneous equilibria<\/dfn><\/dt>\n
\n

equilibria in which reactants and products occupy two or more different phases<\/p>\n<\/dd>\n

high-spin complex<\/dfn><\/dt>\n
\n

complex in which the electrons maximize the total electron spin by singly populating all of the orbitals before pairing two electrons into the lower-energy orbitals<\/p>\n<\/dd>\n

homogeneous catalyst<\/dfn><\/dt>\n
\n

catalyst present in the same phase as the reactants<\/p>\n<\/dd>\n

homogeneous equilibria<\/dfn><\/dt>\n
\n

equilibria in which all reactants and products occupy the same phase<\/p>\n<\/dd>\n

homonuclear diatomic molecule<\/dfn><\/dt>\n
\n

molecule consisting of two identical atoms<\/p>\n<\/dd>\n

Hund\u2019s rule<\/dfn><\/dt>\n
\n

every orbital in a subshell is singly occupied with one electron before any one orbital is doubly occupied, and all electrons in singly occupied orbitals have the same spin<\/p>\n<\/dd>\n

hydrate<\/dfn><\/dt>\n
\n

compound containing one or more water molecules bound within its crystals<\/p>\n<\/dd>\n

hydrogen carbonate<\/dfn><\/dt>\n
\n

\tsalt of carbonic acid, H2CO3 (containing the anion HCO3-) in which one hydrogen atom has been replaced; an acid carbonate; also known as bicarbonate ion<\/em><\/p>\n<\/dd>\n

hydrogen halide<\/dfn><\/dt>\n
\n

binary compound formed between hydrogen and the halogens: HF, HCl, HBr, and HI<\/p>\n<\/dd>\n

hydrogenation<\/dfn><\/dt>\n
\n

addition of hydrogen (H2) to reduce a compound<\/p>\n<\/dd>\n

hydrometallurgy<\/dfn><\/dt>\n
\n

process in which a metal is separated from a mixture by first converting it into soluble ions, extracting the ions, and then reducing the ions to precipitate the pure metal<\/p>\n<\/dd>\n

hydroxide<\/dfn><\/dt>\n
\n

compound of a metal with the hydroxide ion OH\u2212 or the group \u2212OH<\/p>\n<\/dd>\n

hypothesis<\/dfn><\/dt>\n
\n

tentative explanation of observations that acts as a guide for gathering and checking information<\/p>\n<\/dd>\n

inert electrode<\/dfn><\/dt>\n
\n

electrode that conducts electrons to and from the reactants in a half-cell but that is not itself oxidized or reduced<\/p>\n<\/dd>\n

inert gas<\/dfn><\/dt>\n
\n

(also, noble gas) element in group 18<\/p>\n<\/dd>\n

inert pair effect<\/dfn><\/dt>\n
\n

tendency of heavy atoms to form ions in which their valence s electrons are not lost<\/p>\n<\/dd>\n

inner transition metal<\/dfn><\/dt>\n
\n

(also, lanthanide or actinide) element in the bottom two rows; if in the first row, also called lanthanide, or if in the second row, also called actinide<\/p>\n<\/dd>\n

interhalogen<\/dfn><\/dt>\n
\n

compound formed from two or more different halogens<\/p>\n<\/dd>\n

ion-product constant for water (Kw)<\/dfn><\/dt>\n
\n

equilibrium constant for the autoionization of water<\/p>\n<\/dd>\n

ionic bond<\/dfn><\/dt>\n
\n

electrostatic forces of attraction between the oppositely charged ions of an ionic compound<\/p>\n<\/dd>\n

ionic compound<\/dfn><\/dt>\n
\n

compound composed of cations and anions combined in ratios, yielding an electrically neutral substance<\/p>\n<\/dd>\n

ionization energy<\/dfn><\/dt>\n
\n

energy required to remove an electron from a gaseous atom or ion
\nisoelectronic<\/p>\n<\/dd>\n

ionization isomer<\/dfn><\/dt>\n
\n

(or coordination isomer) isomer in which an anionic ligand is replaced by the counter ion in the inner coordination sphere<\/p>\n<\/dd>\n

isoelectronic<\/dfn><\/dt>\n
\n

group of ions or atoms that have identical electron configurations<\/p>\n<\/dd>\n

lanthanide<\/dfn><\/dt>\n
\n

inner transition metal in the top of the bottom two rows of the periodic table<\/p>\n<\/dd>\n

lanthanide series<\/dfn><\/dt>\n
\n

(also, lanthanoid series) lanthanum and the elements in the first row or the f-block, atomic numbers 57\u201371<\/p>\n<\/dd>\n

lattice energy<\/dfn><\/dt>\n
\n

energy requireBorn-Haber cycle<\/a>d to separate one mole of an ionic solid into its component gaseous ions<\/p>\n<\/dd>\n

law<\/dfn><\/dt>\n
\n

statement that summarizes a vast number of experimental observations, and describes or predicts some aspect of the natural world<\/p>\n<\/dd>\n

law of mass action<\/dfn><\/dt>\n
\n

when a reversible reaction has attained equilibrium at a given temperature, the reaction quotient remains constant<\/p>\n<\/dd>\n

Le Ch\u00e2telier\u2019s principle<\/dfn><\/dt>\n
\n

an equilibrium subjected to stress will shift in a way to counter the stress and re-establish equilibrium<\/p>\n<\/dd>\n

lead acid battery<\/dfn><\/dt>\n
\n

rechargeable battery commonly used in automobiles; it typically comprises six galvanic cells based on Pb half-reactions in acidic solution<\/p>\n<\/dd>\n

leveling effect<\/dfn><\/dt>\n
\n

observation that acid-base strength of solutes in a given solvent is limited to that of the solvent\u2019s characteristic acid and base species (in water, hydronium and hydroxide ions, respectively)<\/p>\n<\/dd>\n

Lewis acid<\/dfn><\/dt>\n
\n

any species that can accept a pair of electrons and form a coordinate covalent bond<\/p>\n<\/dd>\n

Lewis acid-base adduct<\/dfn><\/dt>\n
\n

compound or ion that contains a coordinate covalent bond between a Lewis acid and a Lewis base<\/p>\n<\/dd>\n

Lewis acid-base chemistry<\/dfn><\/dt>\n
\n

reactions involving the formation of coordinate covalent bonds<\/p>\n<\/dd>\n

Lewis base<\/dfn><\/dt>\n
\n

any species that can donate a pair of electrons and form a coordinate covalent bond<\/p>\n<\/dd>\n

ligand<\/dfn><\/dt>\n
\n

ion or neutral molecule attached to the central metal ion in a coordination compound<\/p>\n<\/dd>\n

linear<\/dfn><\/dt>\n
\n

shape in which two outside groups are placed on opposite sides of a central atom<\/p>\n<\/dd>\n

linear combination of atomic orbitals<\/dfn><\/dt>\n
\n

technique for combining atomic orbitals to create molecular orbitals<\/p>\n<\/dd>\n

linkage isomer<\/dfn><\/dt>\n
\n

coordination compound that possesses a ligand that can bind to the transition metal in two different ways (CN\u2212 vs. NC\u2212)<\/p>\n<\/dd>\n

lithium ion battery<\/dfn><\/dt>\n
\n

widely used rechargeable battery commonly used in portable electronic devices, based on lithium ion transfer between the anode and cathode<\/p>\n<\/dd>\n

low-spin complex<\/dfn><\/dt>\n
\n

complex in which the electrons minimize the total electron spin by pairing in the lower-energy orbitals before populating the higher-energy orbitals<\/p>\n<\/dd>\n

macroscopic domain<\/dfn><\/dt>\n
\n

realm of everyday things that are large enough to sense directly by human sight and touch<\/p>\n<\/dd>\n

main-group element<\/dfn><\/dt>\n
\n

(also, representative element) element in groups 1, 2, and 13\u201318
\nmetal element that is shiny, malleable, good conductor of heat and electricity<\/p>\n<\/dd>\n

metal (representative)<\/dfn><\/dt>\n
\n

atoms of the metallic elements of groups 1, 2, 12, 13, 14, 15, and 16, which form ionic compounds by losing electrons from their outer s or p orbitals<\/p>\n<\/dd>\n

metalloid<\/dfn><\/dt>\n
\n

element that conducts heat and electricity moderately well, and possesses some properties of metals and some properties of nonmetals
\nnoble gas (also, inert gas) element in group 18<\/p>\n<\/dd>\n

microscopic domain<\/dfn><\/dt>\n
\n

realm of things that are much too small to be sensed directly<\/p>\n<\/dd>\n

microstate<\/dfn><\/dt>\n
\n

possible configuration or arrangement of matter and energy within a system<\/p>\n<\/dd>\n

molar solubility<\/dfn><\/dt>\n
\n

solubility of a compound expressed in units of moles per liter (mol\/L)<\/p>\n<\/dd>\n

molarity (M)<\/dfn><\/dt>\n
\n

unit of concentration, defined as the number of moles of solute dissolved in 1 liter of solution<\/p>\n<\/dd>\n

molecular compound<\/dfn><\/dt>\n
\n

(also, covalent compound) composed of molecules formed by atoms of two or more different elements<\/p>\n<\/dd>\n

molecular orbital<\/dfn><\/dt>\n
\n

region of space in which an electron has a high probability of being found in a molecule<\/p>\n<\/dd>\n

molecular orbital diagram<\/dfn><\/dt>\n
\n

visual representation of the relative energy levels of molecular orbitals<\/p>\n<\/dd>\n

molecular orbital theory<\/dfn><\/dt>\n
\n

model that describes the behavior of electrons delocalized throughout a molecule in terms of the combination of atomic wave functions<\/p>\n<\/dd>\n

molecular structure<\/dfn><\/dt>\n
\n

structure that includes only the placement of the atoms in the molecule<\/p>\n<\/dd>\n

monatomic ion<\/dfn><\/dt>\n
\n

ion composed of a single atom<\/p>\n<\/dd>\n

monodentate<\/dfn><\/dt>\n
\n

ligand that attaches to a central metal through just one coordinate covalent bond<\/p>\n<\/dd>\n

monoprotic acid<\/dfn><\/dt>\n
\n

acid containing one ionizable hydrogen atom per molecule<\/p>\n<\/dd>\n

Nernst equation<\/dfn><\/dt>\n
\n

relating the potential of a redox system to its composition<\/p>\n<\/dd>\n

neutral<\/dfn><\/dt>\n
\n

describes a solution in which [H3O+] = [OH\u2212]<\/p>\n<\/dd>\n

nickel-cadmium battery<\/dfn><\/dt>\n
\n

rechargeable battery based on Ni\/Cd half-cells with applications similar to those of lithium ion batteries<\/p>\n<\/dd>\n

nitrogen fixation<\/dfn><\/dt>\n
\n

formation of nitrogen compounds from molecular nitrogen<\/p>\n<\/dd>\n

nomenclature<\/dfn><\/dt>\n
\n

system of rules for naming objects of interest<\/p>\n<\/dd>\n

nonmetal<\/dfn><\/dt>\n
\n

element that appears dull, poor conductor of heat and electricity
\nperiod (also, series) horizontal row of the periodic table<\/p>\n<\/dd>\n

nonspontaneous process<\/dfn><\/dt>\n
\n

process that requires continual input of energy from an external source<\/p>\n<\/dd>\n

octahedral<\/dfn><\/dt>\n
\n

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<\/p>\n<\/dd>\n

optical isomer<\/dfn><\/dt>\n
\n

(also, enantiomer) molecule that is a nonsuperimposable mirror image with identical chemical and physical properties, except when it reacts with other optical isomers<\/p>\n<\/dd>\n

orbital diagram<\/dfn><\/dt>\n
\n

pictorial representation of the electron configuration showing each orbital as a box and each electron as an arrow<\/p>\n<\/dd>\n

Ostwald process<\/dfn><\/dt>\n
\n

industrial process used to convert ammonia into nitric acid<\/p>\n<\/dd>\n

oxide<\/dfn><\/dt>\n
\n

binary compound of oxygen with another element or group, typically containing O2\u2212 ions or the group \u2013O\u2013 or =O<\/p>\n<\/dd>\n

oxyacid<\/dfn><\/dt>\n
\n

compound that contains hydrogen, oxygen, and one other element, bonded in a way that imparts acidic properties to the compound (ability to release H+ ions when dissolved in water)<\/p>\n<\/dd>\n

oxyanion<\/dfn><\/dt>\n
\n

polyatomic anion composed of a central atom bonded to oxygen atoms<\/p>\n<\/dd>\n

ozone<\/dfn><\/dt>\n
\n

allotrope of oxygen; O3<\/p>\n<\/dd>\n

pairing energy (P)<\/dfn><\/dt>\n
\n

energy required to place two electrons with opposite spins into a single orbital<\/p>\n<\/dd>\n

paramagnetism<\/dfn><\/dt>\n
\n

phenomenon in which a material is not magnetic itself but is attracted to a magnetic field; it occurs when there are unpaired electrons present<\/p>\n<\/dd>\n

passivation<\/dfn><\/dt>\n
\n

metals with a protective nonreactive film of oxide or other compound that creates a barrier for chemical reactions; physical or chemical removal of the passivating film allows the metals to demonstrate their expected chemical reactivity<\/p>\n<\/dd>\n

percent ionization<\/dfn><\/dt>\n
\n

ratio of the concentration of ionized acid to initial acid concentration expressed as a percentage<\/p>\n<\/dd>\n

periodic law<\/dfn><\/dt>\n
\n

properties of the elements are periodic function of their atomic numbers.<\/p>\n<\/dd>\n

periodic table<\/dfn><\/dt>\n
\n

table of the elements that places elements with similar chemical properties close together<\/p>\n<\/dd>\n

peroxide<\/dfn><\/dt>\n
\n

molecule containing two oxygen atoms bonded together or as the anion, \\({\\text{O}}_{2}{}^{2-}\\)<\/p>\n<\/dd>\n

pH<\/dfn><\/dt>\n
\n

logarithmic measure of the concentration of hydronium ions in a solution<\/p>\n<\/dd>\n

photosynthesis<\/dfn><\/dt>\n
\n

process whereby light energy promotes the reaction of water and carbon dioxide to form carbohydrates and oxygen; this allows photosynthetic organisms to store energy<\/p>\n<\/dd>\n

Pidgeon process<\/dfn><\/dt>\n
\n

chemical reduction process used to produce magnesium through the thermal reaction of magnesium oxide with silicon<\/p>\n<\/dd>\n

platinum metals<\/dfn><\/dt>\n
\n

group of six transition metals consisting of ruthenium, osmium, rhodium, iridium, palladium, and platinum that tend to occur in the same minerals and demonstrate similar chemical properties<\/p>\n<\/dd>\n

pnictogen<\/dfn><\/dt>\n
\n

element in group 15<\/p>\n<\/dd>\n

pOH<\/dfn><\/dt>\n
\n

logarithmic measure of the concentration of hydroxide ions in a solution<\/p>\n<\/dd>\n

polar covalent bond<\/dfn><\/dt>\n
\n

covalent bond between atoms of different electronegativities; a covalent bond with a positive end and a negative end<\/p>\n<\/dd>\n

polar molecule<\/dfn><\/dt>\n
\n

(also, dipole) molecule with an overall dipole moment<\/p>\n<\/dd>\n

polyatomic ion<\/dfn><\/dt>\n
\n

ion composed of more than one atom<\/p>\n<\/dd>\n

polydentate ligand<\/dfn><\/dt>\n
\n

ligand that is attached to a central metal ion by bonds from two or more donor atoms, named with prefixes specifying how many donors are present (e.g., hexadentate = six coordinate bonds formed)<\/p>\n<\/dd>\n

polymorph<\/dfn><\/dt>\n
\n

variation in crystalline structure that results in different physical properties for the resulting compound<\/p>\n<\/dd>\n

polymorph silicate<\/dfn><\/dt>\n
\n

compound containing silicon-oxygen bonds, with silicate tetrahedra connected in rings, sheets, or three-dimensional networks, depending on the other elements involved in the formation of the compounds<\/p>\n<\/dd>\n

primary cell<\/dfn><\/dt>\n
\n

nonrechargeable battery, suitable for single use only<\/p>\n<\/dd>\n

pure covalent bond<\/dfn><\/dt>\n
\n

(also, nonpolar covalent bond) covalent bond between atoms of identical electronegativities<\/p>\n<\/dd>\n

rare earth element<\/dfn><\/dt>\n
\n

collection of 17 elements including the lanthanides, scandium, and yttrium that often occur together and have similar chemical properties, making separation difficult<\/p>\n<\/dd>\n

reaction quotient (Q)<\/dfn><\/dt>\n
\n

mathematical function describing the relative amounts of reactants and products in a reaction mixture; may be expressed in terms of concentrations (Qc) or pressures (Qp)<\/p>\n<\/dd>\n

representative element<\/dfn><\/dt>\n
\n

(also, main-group element) element in columns 1, 2, and 12\u201318 series (also, period) horizontal row of the period table<\/p>\n<\/dd>\n

representative metal<\/dfn><\/dt>\n
\n

metal among the representative elements<\/p>\n<\/dd>\n

reversible process<\/dfn><\/dt>\n
\n

process that takes place so slowly as to be capable of reversing direction in response to an infinitesimally small change in conditions; hypothetical construct that can only be approximated by real processes<\/p>\n<\/dd>\n

reversible reaction<\/dfn><\/dt>\n
\n

chemical reaction that can proceed in both the forward and reverse directions under given conditions<\/p>\n<\/dd>\n

s-p mixing<\/dfn><\/dt>\n
\n

change that causes \u03c3p orbitals to be less stable than \u03c0p orbitals due to the mixing of s and p-based molecular orbitals of similar energies.<\/p>\n<\/dd>\n

sacrificial anode<\/dfn><\/dt>\n
\n

electrode constructed from an easily oxidized metal, often magnesium or zinc, used to prevent corrosion of metal objects via cathodic protection<\/p>\n<\/dd>\n

salt bridge<\/dfn><\/dt>\n
\n

tube filled with inert electrolyte solution<\/p>\n<\/dd>\n

scientific method<\/dfn><\/dt>\n
\n

path of discovery that leads from question and observation to law or hypothesis to theory, combined with experimental verification of the hypothesis and any necessary modification of the theory<\/p>\n<\/dd>\n

second law of thermodynamics<\/dfn><\/dt>\n
\n

all spontaneous processes involve an increase in the entropy of the universe<\/p>\n<\/dd>\n

second transition series<\/dfn><\/dt>\n
\n

transition elements in the fifth period of the periodic table (second row of the d-block), atomic numbers 39\u201347<\/p>\n<\/dd>\n

secondary cell<\/dfn><\/dt>\n
\n

battery designed to allow recharging<\/p>\n<\/dd>\n

selective precipitation<\/dfn><\/dt>\n
\n

process in which ions are separated using differences in their solubility with a given precipitating reagent<\/p>\n<\/dd>\n

silicate<\/dfn><\/dt>\n
\n

compound containing silicon-oxygen bonds, with silicate tetrahedra connected in rings, sheets, or three-dimensional networks, depending on the other elements involved in the formation of the compounds<\/p>\n<\/dd>\n

smelting<\/dfn><\/dt>\n
\n

\tprocess of extracting a pure metal from a molten ore<\/p>\n<\/dd>\n

solubility product constant (Ksp)<\/dfn><\/dt>\n
\n

equilibrium constant for the dissolution of an ionic compound<\/p>\n<\/dd>\n

solute<\/dfn><\/dt>\n
\n

solution component present in a concentration less than that of the solvent<\/p>\n<\/dd>\n

solvent<\/dfn><\/dt>\n
\n

solution component present in a concentration that is higher relative to other components<\/p>\n<\/dd>\n

spectrochemical series<\/dfn><\/dt>\n
\n

ranking of ligands according to the magnitude of the crystal field splitting they induce<\/p>\n<\/dd>\n

spontaneous change<\/dfn><\/dt>\n
\n

process that takes place without a continuous input of energy from an external source<\/p>\n<\/dd>\n

standard cell potential<\/dfn><\/dt>\n
\n

the cell potential when all reactants and products are in their standard states (1 bar or 1 atm or gases; 1 M for solutes), usually at 298.15 K<\/p>\n<\/dd>\n

standard electrode potential<\/dfn><\/dt>\n
\n

electrode potential measured under standard conditions (1 bar or 1 atm for gases; 1 M for solutes) usually at 298.15 K<\/p>\n<\/dd>\n

standard entropy (S\u00b0)<\/dfn><\/dt>\n
\n

entropy for one mole of a substance at 1 bar pressure; tabulated values are usually determined at 298.15 K<\/p>\n<\/dd>\n

standard entropy change (Delta S\u00b0)<\/dfn><\/dt>\n
\n

change in entropy for a reaction calculated using the standard entropies<\/p>\n<\/dd>\n

standard free energy change (\u0394G\u00b0)<\/dfn><\/dt>\n
\n

change in free energy for a process occurring under standard conditions (1 bar pressure for gases, 1 M concentration for solutions)<\/p>\n<\/dd>\n

standard free energy of formation (Gf)<\/dfn><\/dt>\n
\n

change in free energy accompanying the formation of one mole of substance from its elements in their standard states<\/p>\n<\/dd>\n

standard hydrogen electrode (SHE)<\/dfn><\/dt>\n
\n

half-cell based on hydrogen ion production, assigned a potential of exactly 0 V under standard state conditions, used as the universal reference for measuring electrode potential<\/p>\n<\/dd>\n

steel<\/dfn><\/dt>\n
\n

material made from iron by removing impurities in the iron and adding substances that produce alloys with properties suitable for specific uses<\/p>\n<\/dd>\n

stepwise ionization<\/dfn><\/dt>\n
\n

process in which a polyprotic acid is ionized by losing protons sequentially<\/p>\n<\/dd>\n

strong-field ligand<\/dfn><\/dt>\n
\n

ligand that causes larger crystal field splittings<\/p>\n<\/dd>\n

superconductor<\/dfn><\/dt>\n
\n

material that conducts electricity with no resistance<\/p>\n<\/dd>\n

symbolic domain<\/dfn><\/dt>\n
\n

specialized language used to represent components of the macroscopic and microscopic domains, such as chemical symbols, chemical formulas, chemical equations, graphs, drawings, and calculations<\/p>\n<\/dd>\n

T_2g orbitals<\/dfn><\/dt>\n
\n

set of three d orbitals aligned between the Cartesian axes for coordination complexes; in octahedral complexes, they are lowered in energy compared to the eg orbitals according to CFT<\/p>\n<\/dd>\n

tetrahedral<\/dfn><\/dt>\n
\n

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\u00b0 angles between each pair and the central atom<\/p>\n<\/dd>\n

theory<\/dfn><\/dt>\n
\n

well-substantiated, comprehensive, testable explanation of a particular aspect of nature<\/p>\n<\/dd>\n

third law of thermodynamics<\/dfn><\/dt>\n
\n

entropy of a perfect crystal at absolute zero (0 K) is zero<\/p>\n<\/dd>\n

third transition series<\/dfn><\/dt>\n
\n

transition elements in the sixth period of the periodic table (third row of the d-block), atomic numbers 57 and 72\u201379<\/p>\n<\/dd>\n

titration curve<\/dfn><\/dt>\n
\n

plot of some sample property (such as pH) versus volume of added titrant<\/p>\n<\/dd>\n

trans configuration<\/dfn><\/dt>\n
\n

configuration of a geometrical isomer in which two similar groups are on opposite sides of an imaginary reference line on the molecule<\/p>\n<\/dd>\n

transition metal<\/dfn><\/dt>\n
\n

element in groups 3\u201312 (more strictly defined, 3\u201311; see chapter on transition metals and coordination chemistry)<\/p>\n<\/dd>\n

trigonal bipyramidal<\/dfn><\/dt>\n
\n

shape in which five outside groups are placed around a central atom such that three form a flat triangle with 120\u00b0 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<\/p>\n<\/dd>\n

trigonal planar<\/dfn><\/dt>\n
\n

shape in which three outside groups are placed in a flat triangle around a central atom with 120\u00b0 angles between each pair and the central atom<\/p>\n<\/dd>\n

triprotic acid<\/dfn><\/dt>\n
\n

acid that contains three ionizable hydrogen atoms per molecule<\/p>\n<\/dd>\n

valence electrons<\/dfn><\/dt>\n
\n

electrons in the outermost or valence shell (highest value of n) of a ground-state atom<\/p>\n<\/dd>\n

valence shell<\/dfn><\/dt>\n
\n

outermost shell of electrons in a ground-state atom<\/p>\n<\/dd>\n

valence shell electron-pair repulsion theory (VSEPR)<\/dfn><\/dt>\n
\n

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<\/p>\n<\/dd>\n

vector<\/dfn><\/dt>\n
\n

quantity having magnitude and direction<\/p>\n<\/dd>\n

weak-field ligand<\/dfn><\/dt>\n
\n

ligand that causes small crystal field splittings<\/p>\n<\/dd>\n<\/dl>\n

definition<\/span>