as chemistry glossary

7/31/2019 As Chemistry Glossary

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Key term Definition

accuracy The degree of conformity of a mea

actinides The bottom row of f block element

activated complex A transitional structure in a chemi

activation energy or EA The minimum energy required to s

addition polymerisation A polymerisation reaction where

addition reaction A reaction where two molecules c

alcohols Homologous series of organic molaldehydes Homologous series of organic mol

alicyclics Organic molecules containing clos

aliphatic Organic molecules containing strai

aliphatic hydrocarbons Hydrocarbons containing closed ri

aliquots Equal measured volume of solutio

alkaline earth metals A family of metals in Group 2 of th

alkanes Simplest homologous series of hyd

alkenes Homologous series of hydrocarbo

alkyl group An alkane molecule that has lost a

alkynes Homologous series of hydrocarbo

allotropes Forms of the same element in the

alpha radiation Two protons and two neutrons (he

amorphous carbon Non-crystalline forms of carbon e.

anabolic steroids Hormones used to encourage the

anthropogenic climate change Climate change due to activities of

antioxidants Compounds which react with and i

Ar Symbol for relative atomic mass.

arenes Organic molecules derived from th

atom The smallest complete unit of an el

atom economy Measure of how efficiently a reacti

atomic crystals/giant atomic structures Atoms held together by covalent b

atomic mass unit The mass of a carbon-12 atom diviatomic number Z The number of protons in an atom

atomic radius The distance of closest approach b

atomisation The breaking of bonds in a molecul

Avogadro constant The number of atoms of carbon in

Avogadro s law All gases contain equal numbers of

balanced equation A chemical equation where the nu

base The number base.

base peak The largest peak (or the greatest tr

base units The basic SI units of measurement.

bent linear A molecule where three atoms are

benzene Organic compound with the molec

beta radiation High energy electrons.

bio polymers Polymers made from materials pro

biodegradable Can be broken down by living orga

bio fuels Fuels made from living material e.

blocks Regions of the periodic table.

body centred cubic structure Arrangement of ions in a lattice w

bomb calorimeter Calorimeter which gives accurate

bond angles Angle between two bonds in a mol


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bond dissociation enthalpy The energy required to break a par

bond energy The amount of energy needed to

bond enthalpy The energy contained in a chemica

bond fission Breaking the bonds between atom

bond length The average distance between the

Born Haber cycle Special type of enthalpy level diagr

boundary Separates the system from the sur

brittle Breaks easily when hit.calorimeter Insulated container used to measu

carbanion A species containing a negative ch

carbocation / carbonium ion The positively charged ion left whe

carbon capture A process that removes carbon dio

carbon footprint Measure of the impact of human a

carbon neutral When the amount of carbon dioxi

carbon offsetting A method of reducing the carbon f

carbon sink A reservoir of carbon compounds.

carboxylic acids Homologous series of organic mol

carcinogenic Causes cancer.

cat cracker Industrial vessel where catalytic crcatalyst A substance which alters the rate

catalytic cracking or cat cracking Breaking down long chain alkanes i

catalytic reforming Process which involves breaking d

cellulose A polymer of glucose molecules fo

centres of charge Parts of a molecule where positive

chain reaction A reaction in which a change in on

charge density The amount of electric charge per

chemical bonds Forces holding atoms together.

chemical properties Properties which affect the way in

chemical/feedstock recycling Chemically breaking down polyme

chlorofluorocarbons or CFCs Compounds containing fluorine, c

cis trans isomerism Traditional method of naming geo

closed system A system which can exchange ene

collision theory Theory accounting for the effects

colorimeter An instrument that measures the a

colorimetric analysis Analysis carried out using a colori

completion reaction A reaction where all of the reactan

concentration Measure of the amount of a solute

condensation polymerisation A polymerisation reaction where,

condensation reaction A reaction where two molecules c

conductimetric analysis Analysis carried out by measuring

contrails Condensation trails or artificial cirr

coordination number The number of close neighbours tocorrosive A substance which breaks down or

Coulomb s law Law which states that the force of

covalent bond/ing A chemical bond formed when tw

covalent bonds Strong bonds which result from sh

crude oil/petroleum Unprocessed oil, a fossil fuel extra

curly arrows Symbol used to represent the mov

d block Region of the periodic table contai

d block elements Elements with the outermost elect


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dative covalent bond A dative covalent bond is a covale

Debye or D Unit of dipole moment.

delocalised electrons Electrons which are not associated

derived units Units of measurement derived fro

diatomic A molecule containing two atoms.

diesel oil One of the heavier fractions of cru

dimers Pairs of molecules held together b

dipole A positive charge and a negative cdipole interactions Forces of attraction between char

dipole moment For a pair of opposite charges of m

displacement reaction A reaction where a more reactive

displayed formula Formula which shows both the rel

disproportionation Simultaneous oxidation and reduct

dissipated Energy irreversibly lost to the syst

dot and cross diagrams A way of representing electrons to

double bond The bond formed when two atoms

double salt Crystal containing two different sal

ductile Can be drawn out into wires.

dynamic equilibrium See equilibrium.E isomer Isomer with higher priority groups

E Z isomerism IUPAC system for naming geometri

electron cloud Arrangement of electrons in an at

electron density The areas in the electron cloud of

electron density map or plot Map plotting the areas where the

electron pair repulsion theory The theory used to explain the sha

electron spin The rotation of electrons clockwis

electronegativity The tendency of the atoms of an el

electronic configuration The arrangement of electrons in th

electronic structure The arrangement of electrons in a

electrons Sub-atomic particles with a negati

electrophiles Positively polarised, electron seeki

electrophilic Attracted to electrons.

electrophilic addition reaction A reaction in which an electrophile

electrophilic attack Effect of an electrophile on a mole

electrostatic Relating to electric charges that do

electrostatic theory Like charges repel, opposite charg

element A substance that cannot be broken

elimination reaction A reaction in which a small molecu

empirical formula Simplest formula of a compound s

end point The stage in the reaction where th

endothermic reaction A reaction which takes in energy fr

energetic/thermodynamic stability Stability of a compound with respeenergetics The study of energy transfers bet

energy recovery Methods of recovering some of th

entgegen Opposite

enthalpy change The change in the energy content

enthalpy change of reaction The energy change which takes pla

enthalpy H The energy content of a system at

enthalpy level diagram Diagram used to represent the ent

epitestosterone Hormone similar to testosterone.


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equilibrium A situation with a reversible reacti

equilibria Plural of equilibrium.

ethers A homologous series.

excited Term used to describe electrons w

exothermic reaction A reaction which releases energy i

f block Region of the periodic table contai

f block elements Elements with the outermost elect

face centred cubic structure Arrangement ions in a lattice wherfingerprint region The region to the right-hand side o

fire retardants Materials that inhibit or resist the

first ionisation energy The energy needed to remove the

flame photometer An instrument used for measuring

flame test Test used to detect certain metal c

fraction The liquid collected at a particular

fragmentation The process in a mass spectromet

free radicals Atom or molecule with an unpaire

fullerenes A family of ball-shaped carbon mol

functional group Atom or group of atoms which is t

gamma radiation A subset of electromagnetic radiatigas oil Similar to diesel oil but less useful i

gasification Breakdown of solid hydrocarbons i

gasoline A mixture of liquid hydrocarbons

general formula A formula which applies to all me

geometric isomers Stereoisomer and isomer in space.

giant lattice structure Arrangement of ions in an ionic su

global warming A measured increase in the tempe

global warming potential or GWP A measure of the effectiveness of

greenhouse effect The trapping of some of the energ

greenhouse gases Atmospheric gases which reduce t

ground state The lowest energy state of an ato

groups Vertical columns of the periodic ta

half equations Part of an equation for a redox rea

half-life The time it takes for half the atom

halogenoalkanes Homologous series of organic mol

halogens A family of reactive non-metals in

hazard Potential to do harm.

heat capacity C The amount of heat required to rai

heat exchanger A device built for efficient heat exc

Hess's law Law stating that the total enthalpy

heterogeneous reaction A reaction which takes place at th

heterolytic fission Fission which involves the unequal

high density polythene or HDPE Ethene polymer with relatively fehomogeneous reaction A reaction which takes place in a si

homologous series Family of organic molecules.

homolytic fission Fission which involves the equal sh

Hund's rule Rule stating that when electrons a

hydration The process where water molecul

hydration enthalpy Energy released when 1 mole of g

hydrocarbons Organic compounds with molecule

hydrochlorofluorocarbons or HCFCs A class of haloalkanes where not al


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hydrogen bond A special type of dipole-dipole forc

hydrogen cell A new technology for powering ve

hydrolysis A reaction where a substance is spl

hydroxyl group An O-H functional group.

immiscible Liquids which do not mix but form

incomplete combustion Burning when the supply of oxyge

index The power to which a base numbe

induced dipole A dipole set up by the close proximinert Non-reactive.

infrared spectrometer An instrument for producing an inf

infrared spectrum A graph showing the record produ

initial rate of reaction The rate of reaction at the start of

initiate Start/supply the initial energy for a

inorganic chemistry Study of all the 91 naturally organi

instantaneous dipole A temporary dipole set up in a mol

instantaneous dipole induced dipole interactions Forces between neighbouring mol

intermolecular forces Forces between molecules.

intramolecular forces Forces within molecules.

ion An atom which has lost or gainedion microscope A microscope which uses helium io

ionic/electrovalent bond Strong forces of attraction betwee

ionic bonding A chemical bond formed when ato

ionic crystals Crystals formed by giant ionic latti

ionic equation Reaction equation which only sho

ionic radius Term used to describe the size of i

ionisation The complete removal of an electr

ionisation energy The energy change associated wit

irritant A substance which causes irritatio

isoelectronic An ion with the same number and

isolated system A system where the boundary pre

isomerism Where two or more compounds h

isomers Two or more compounds with the

isotopes Atoms of the same element with t

IUPAC International Union of Pure and Ap

kerosene The fraction of crude oil used for ai

ketones Homologous series of organic mol

kinetic stability When the activation energy of a re

lanthanides The top row of f block elements.

lattice Structural arrangement of a solid.

lattice energy The energy released when an ionic

law of octaves Law developed in an attempt to ar

Le Chatelier's principle When an equilibrium reaction mixtlife cycle assessment/analysis or LCA The investigation and valuation of

lime water A solution of calcium hydroxide in

line/emission spectrum The pattern which results from the

linear All of the atoms in a molecule are i

liquid petroleum gas or LPG Propane which is liquefied at low t

London dispersion forces The forces that exist in non-polar

lone pair Two non-bonding electrons in a m

low density polythene Ethene polymer with branched ch


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macroscopic properties Those properties that an external

malleable Can be hammered into sheets

Markovnikov s rule Rule that states that when a hydro

mass number A The number of neutrons plus the n

mass spectrometer Instrument for obtaining a mass sp

mass spectrum The data produced by a mass spec

Maxwell Boltzman model A model for expressing the distrib

mean bond enthalpy The mean value of the bond dissocmechanical recycling Physically breaking down plastics i

melting temperature The temperature at which a pure s

metallic bonding Bonding in metals with positive m

metalloids Elements which aren't metals but

metals Elements which are good conduct

micromoles 1*10^-6 moles.

microscopic processes Processes on a molecular scale.

millimoles 1*10^-3 moles.

miscible Liquids which completely mix to fo

molar/molarity Concentration in mole dm^-3

molar enthalpy of vaporisation Energy required to change 1 molemolar mass M The relative atomic or molecular m

molar solution A solution of concentration 1 mola

molar volume Vm The volume occupied by a mole of

mole or mol The amount of substance that con

molecular crystals/giant molecular structures Covalently bonded molecules held

molecular equation Reaction equation which shows th

molecular formula Formula of a compound showing h

molecular ion peak The peak corresponding to the M+

moles per cubic decimetre Measure of the concentration of a

monomer A small molecule, for example an a

nanoparticles Small particles with at least one di

nanoprobes Devices for seeing very small objec

nanorods A material made by compressing C

nanotubes Cylindrical carbon molecules whic

natural climate change Climate change due to naturally oc

natural gas A gaseous fossil fuel found in asso

natural pesticides Pesticides derived from plants or o

neutrons Electrically neutral sub-atomic part

noble gases Group 8, unreactive gases.

non aqueous solvents A solvent other than water.

non metals All the elements which are not me

nucleons The sub-atomic particles found in t

nucleophile An electron donor, attracted to ponucleophilic attack Effect of a nucleophile on an ion in

octane rating Rating for fuel which indicates the

octet rule Rule stating that when elements r

orbital The region where an electron is m

organic chemistry Study of carbon compounds with t

overall ionic equation Overall reaction equation showing

oxidation Reaction in which electrons are los

oxidation numbers The charge that an element would


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oxidising agent A substance which oxidises anothe

p block Region of the periodic table contai

p block elements Elements with their outermost ele

paraffins Old, non-systematic name for the

parts per million ppm Mass of the solute/total mass * 10

peaks Characteristic wavelength of a vibr

pentagonal bipyramid A molecule with three bonds in a p

percentage transmission The variable recorded on the y-axiperiodic law Law stating that the properties of

periodic properties Properties which show clear patte

periodic table Table arranging the elements in or

periodicity Repeating patterns of elements in

periods Horizontal rows of the periodic tab

permanent dipole A distribution of charge within a m

pesticides Chemicals that kill animal pests.

physical properties Properties which do not involve th

pi bond A double carbon to carbon bond, i.

polar bond A covalent bond where the pair of

polar molecule A molecule with an overall dipole ,pole One half of a dipole.

polychloroethene Polymer of chloroethene.

polyethene Polymer made from repeating eth

polymer Large molecule made up of long ch

polymerisation reaction A reaction in which many monome

polypropene Polymer of propene.

position of equilibrium The extent to which a reaction has

post transition metals Metals found to the right hand sid

precise results Results made to the maximum acc

primary alcohol An alcohol where the hydroxyl gro

primary distillation Process by which crude oil is turne

primary halogenoalkanes Halogen atom is attached to a carb

principal quantum number n The number assigned to electron s

principle of conservation of energy Principle stating that the total ene

propagation reaction A reaction which sets of other reac

protons Sub-atomic particle with positive c

pyramidal molecule A molecule such as ammonia with

pyrolisis Method of breaking down polyme

pyrolisis/bio oil An alternative fuel extracted by py

qualitative Identifying the different constitue

quantitative Measuring the different quantities

quantum mechanics Branch of physics needed to under

quench Cooling a sample rapidly to slow allquicklime The old name for calcium oxide.

radioactive decay The process by which an unstable

radiocarbon dating Using the ratio of C-12 to C-14 to d

rate of reaction The speed at which a reaction hap

reaction mechanism Mechanism by which a reaction ta

reaction profile Graph that shows the change in en

reactive metals The s block elements.

redox reaction A reaction where oxidation and re


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reducing agent A substance which reduces anothe

reduction Reaction in which electrons are gai

refinery gas The lightest fraction of crude oil (C

reflux condenser A vertical condenser which conden

relative abundance Measure of the percentage of diff

relative atomic mass or RAM The atomic mass of an atom relati

relative atomic mass scale The scale by which chemists comp

relative formula mass The sum of all the relative atomicrelative greenhouse factor A comparison of the effect differe

relative molecular mass or Mr The sum of all the relative atomic

reliable results Results that if repeated will give th

residue A viscous mixture of hydrocarbons

risk The chance of a hazard causing ha

risk assessment Identifying the risks associated wit

rock salt structure The packing of ions found in sodiu

s block Region of the periodic table contai

s block elements Elements with the outermost elect

saturated Containing only C-C bonds.

second ionisation energy The energy needed to remove a sesecondary alcohol An alcohol where the hydroxyl gro

secondary halogenoalkanes Halogen atom is attached to a carb

shells The regions in which electrons are

sigma bond Single C-C bond.

skeletal formula Formula which simply shows the b

slaked lime Old name for calcium hydroxide.

slaking The exothermic process taking pla

solubility Mass of a solute dissolving in 100g

solute Solid, liquid or gas dissolved in a li

solution A liquid containing a dissolved soli

solvent Liquid in which substances dissolv

space filling models Models showing the shape of mol

specific heat capacity c The heat capacity per unit mass of

spectator ions Ions which appear in the same for

stability Description of how readily a comp

standard enthalpy change of atomisation The enthalpy change when 1 mole

standard enthalpy change of combustion The enthalpy change when 1 mole

standard enthalpy change of formation The enthalpy change when 1 mole

standard enthalpy change of neutralisation The enthalpy change when 1 mole

standard enthalpy change of reaction The enthalpy change of a reaction

standard solution A solution of known concentration

standard temperature and pressure STP Conditions used for measuring the

starch A polymer of glucose molecules.state symbols Symbols used to indicate the physi

steady state A situation in which all variables ar

stereoisomers 2+ compounds with same molecul

structural formula Formula which shows both the nu

structural isomers 2+ compounds with same molecul

subshell Regions of differing energy within

substitution reaction A reaction in which an atom or gro

surroundings Everything around a chemical reac


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syngas Mixture of hydrogen and carbon m

synthesise To make in a laboratory.

synthetic pesticides Pesticides which are not naturally

system A chemical reaction.

Systeme International or SI The common internationally used

termination A reaction which completes a chai

tertiary alcohol An alcohol where the hydroxyl gro

tertiary halogenoalkanes Halogen atom is attached to a carbtestosterone Male sex hormone.

thermochemistry The study of energy transfers in ch

titration A process for finding the exact vol

transition Energy changes which take place

transition metals Another name for the d block elem

triads Group of three elements in an earl

trigonal planar A triangular shape with all three li

triple bond The bond formed when two atoms

unsaturated Containing at least on C=C bond.

unstable An atom in which the forces which

Van der Waals forces Very weak attractive forces betwevolatility The ease with which a liquid turns

volumetric/titrimetric analysis Chemical procedure used to deter

weighted mean A mean based on both the abunda

yield The quantity of a product obtained

Z isomer Isomer with both higher priority gr

zussammen Together.


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sured or calculated quantity to its actual (true) value.

s. These are all radioactive.

al reaction that results from an effective collision between molecules and that persists while old bonds a

tart a reaction by breaking bonds.

onomers join together and the polymer is the only product.

mbine to form a single product.

cules with an -OH functional group.cules containing the carbonyl group positioned at the end of the carbon chain.

d rings of carbon atoms which may contain single or multiple carbon-carbon bonds.

ght or branched chain carbon skeletons which may contain single or multiple carbon-carbon bonds.

gs of carbon atoms which may contain single or multiple carbon-carbon bonds.

.

e periodic table.

rocarbons with general formula CnH2n+2

s containing a double carbon-carbon double bond with general formula CnH2n

hydrogen atom to attach to another carbon chain.

s containing at least one triple carbon-carbon double bond with general formula CnH2n-2

same physical state.

lium nuclei).

. soot.

rowth of muscle and body mass.

human beings e.g. burning fossil fuels, deforestation.

nactivate free radicals.

e benzene molecule containing a benzene ring with 6 carbon atoms in their structure.

lement. It consists of protons and neutrons in the nucleus orbited by electrons.

ion turns reactants into desired products. Equals the molecular mass of the desired product divided by th

onds in a giant lattice structure.

ded by 12.of an element.

etween two atoms.

le to leave atoms.

exactly 12g of carbon-12 i.e. 6.02*1023

molecules at the same temperature and pressure.

mbers of atoms are equal on both sides and all are in the form in which they undergo the reaction (i.e. co

ough) on the ir spectrum.

.

joined together but not in a straight line e.g. water.

ular formula C6H6.

duced from living, renewable resources such as plants.

nisms.

. ethanol from the fermentation of maize.

ere each ion has 8 nearest neighbours.

easure of enthalpy changes, particularly when a substance is burnt in oxygen.

ecule.


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ticular bond or the energy released when a bond is formed.

ake or break a bond.

l bond.

s in a molecule.

nuclei of atoms in a molecule.

am used to calculate the lattice energy of substances.

roundings in thermochemistry.

re enthalpy change of a reaction.

rge produced by the heterolytic fission of a covalent bond.

n carbon has lost electrons in an electrophilic attack. A species containing a positive charge produced by

xide and stops it from being emitted.

ctivity in terms of the amount of greenhouse gases produced.

e absorbed when a raw material is grown or a fuel is formed equals the amount of carbon dioxide forme

ootprint e.g. by planting trees.

cules with a -COOH functional group.

acking takes place.f a chemical reaction without being used up.

into shorter chain molecules which are more useful as fuels and as compounds in industry. Catalysts such

wn the longer straight chain molecules from crude oil and reforming them into shorter branched chain

und in the stems of plants.

and negative charge is concentrated.

e molecule causes changes in many other molecules until eventually a stable molecule is formed.

unit volume.

which an element or compound reacts with other substances.

rs into monomer units for reuse.

lorine and carbon only. They were formerly used in industry e.g. as refrigerants, propellants and cleanin

etric isomers based on the arrangements of groups around a rigid bond.

gy with the surroundings but not matter.

f concentration, temperature, surface area and catalysts on reaction rates.

bsorbance of particular wavelengths of light by a specific solution. It is most commonly used to determin

eter.

ts have been turned into products.

dissolved in a solvent to form a solution.

small molecule such as water or hydrogen chloride is lost when two monomer molecules combine.

mbine to form a larger molecule and a small molecule such as water or hydrogen chloride is lost.

hanges in conductivity of solutions.

us clouds made by the exhaust of aircraft engines which precipitate a stream of tiny ice crystals in moist,

an ion in a lattice structure.destroys materials including skin.

attraction between ions is related to the charge on the ions and the distance between them.

or more atoms share electrons to gain a full, outer stable shell.

aring electrons during covalent bonding.

ted from underground.

ement of a pair of electrons.

ning elements with their outer electrons in the d subshell.

ron in the d subshell.


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t bond where both of the shared electrons come from the same atom.

with one particular atom but are free to move.

the basic SI units.

de oil used in diesel engines and as fuel for industrial boilers. Can also be used in a catalytic cracker to yie

dative covalent bonds.

harge separated by a short distance.e centres in different molecules.

agnitude of the dipole moment is defined as the magnitude of the charge times the distance between th

lement displaces a less reactive element in an aqueous solution.

tive placing of the atoms and the number of bonds between them.

ion.

m.

model bonding between atoms.

share two pairs of electrons.

lts in a 1:1 ratio.

on opposite sides of a rigid bond.

ic isomers based on the atomic numbers of the atoms attached around a rigid bond.

m.

n atom where the electrons are most likely to be found.

robability of finding an electron is highest. The diffraction patterns produced when x-rays are passed thr

pes of molecules using the idea that electron pairs are arranged as far from each other as possible.

or anticlockwise creating a magnetic field.

lement to gain electrons.

eir subshells and orbitals.

atoms in its main energy levels and sub levels.

e charge which orbit the nucleus of an atom.

ng groups e.g. H+

is attracted to an area of high electron density and joins onto the molecule.

cule in a reaction, removing electrons.

not move.

es attract.

down chemically into simpler substances. All the atoms of an element contain the same number of prot

le is removed from an organic molecule to produce a double bond.

owing the whole number ratios of the atoms present.

e indicator changes colour showing that exact reacting volumes of the two solutions are present.

om the surroundings.

ct to its elements in terms of bond enthalpy.een reacting chemicals and their surroundings.

energy used in the production of polymer products by burning them as fuels for electricity production e

f a system held at constant pressure.

ce during a chemical reaction.

constant pressure.

halpy changes during a reaction.


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n where the rate of forward reaction is equal to the rate of the reverse reaction so there is no apparent

hen they are raised from one energy level to another within an atom.

to the surroundings.

ning elements with their outer electrons in the f subshell.

ron in the f subshell.

e each ion has 6 nearest neighbours.f the ir spectrum which usually contains a very complicated series of absorptions mainly due to all mann

pread of fire.

first electron from an atom.

the spectral intensity of metals present in the metallic salt.

ations by observing the colour of the flame.

temperature during primary distillation.

r that causes a positive ion to split into pieces, one of which is a positive fragment ion.

electron e.g. one formed on the breaking of a covalent bond.

ecules with the commonest one C60 called buckminsterfullerene.

pical of a particular homologous series and which plays an important part in determining the chemical p

ion.in a cracker.

n a limited supply of oxygen to produce syngas.

idely used as motor fuel (C5-C10).

bers of a homologous series and describes the number of carbon atoms and their relationship to the oth

A chemical compound which has the same molecular formula as another but a different geometric confi

stance.

rature at the surface of the Earth over a period of time.

ifferent gases have in increasing global warming.

absorbed by the Earth from the Sun an reradiated from the surface by greenhouse gases in the atmosp

he loss of heat by radiation from the Earth's atmosphere contributing to the greenhouse effect e.g. carbo

.

ble.

ction showing oxidation or reduction of one species. Two half equations added together can produce an i

in a sample of radioactive material to decay.

cules in which one or more of the hydrogen atoms within an alkane has been replace by a halogen atom

roup 7 of the periodic table.

se the temperature of an object by 1K.

hange from one place to another. In a chemical factory waste energy from one place can be used efficie

change for a reaction is independent of the route taken.

boundary of two phases.

sharing of the electrons of a covalent bond, so that both electrons go to one atom when the covalent bo

branched chains so relatively dense with higher melting point than LDPE.ngle phase.

aring of electrons in a bond so that each atom receives one electron when the bond is broken.

e placed in a set or orbitals with equal energy, they spread out to maximise the number of unpaired elec

s arrange themselves around an ion in a solution.

seous ions are dissolved in excess water.

s containing only carbon and hydrogen.

ll hydrogen has been replaced by chlorine or fluorine. They are used primarily as chlorofluorocarbon (CF


14/32

e that exists between an electronegative atom and a hydrogen atom bonded to another electronegative

hicles based on the oxidation of hydrogen with water as the waste product.

lit up by water (or dilute acid or alkali).

separate layers.

is limited.

r is raised.

ity of strong charge.

rared spectrum.

ced when an infrared spectrometer scans an ir wavelength and the detector records how strongly the sa

a reaction.

reaction.

c chemical elements and their compounds, including carbon and its oxides and carbonates.

ecule.

cules that provide the means of bringing non-polar molecules together in a liquid at low temperatures.

lectrons to take a positive or negative charge.ns instead of light to form an image giving very high levels of magnification.

n oppositely charged ions formed during ionic bonding. The electrostatic forces two oppositely charged i

ms gain or lose electrons to form positive or negative ions. The loss or gain in electrons gives the ion a co

es.

s the ions involved in a reaction.

ns.

on from an atom.

the removal of an electron from an atom or ion.

of the skin.

arrangement of electrons as an atom of another element.

ents matter and energy entering and leaving.

ve the same molecular formula but with the atoms arranged differently.

same molecular formula but with the atoms arranged differently.

e same atomic number but with different numbers of neutrons giving them different mass numbers.

plied Chemistry.

ircraft fuel and also as a source of other useful chemicals in the cracking process.

cules containing at least one carbonyl group which is never positioned at the end of the carbon chain.

action is so large that no molecules in the reaction mixture have sufficient energy to overcome it and so

lattice is formed. A measure of the strength of bonds in an ionic compound. It is equivalent to the amou

range the elements in order of atomic masses.

ure is subjected to a change in conditions, the composition adjusts to counteract the change.the environmental impacts of a given product or service caused or necessitated by its existence.

water used as a positive test for carbon dioxide gas.

light given out by a gas when an electrical charge is passed through it to form a spectrum.

n a straight line.

emperatures and high pressures for storage and transport.

olecules that involve an accidental dipole that induces a momentary dipole in a neighbour.

lecule.

ins: low density, low m.p.


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bserver can see and measure with a naked eye.

gen halide is added to an alkene, the hydrogen is most likely to add to the carbon atom which already ha

umber of protons in the nucleus of an atom.

ectrum that can be used to measure the relative masses of isotopes or to find the relative abundance of

rometer.

tion of energy among the molecules in a gas in thermal equilibrium.

iation enthalpy of a particular type of bond over a wide range of different compounds.to smaller pieces before reprocessing.

olid is in equilibrium with a pure liquid at atmospheric pressure.

tal ions embedded in a sea of delocalised electrons.

hich have some characteristics of a metal e.g. conducts electricity.

rs of heat and electricity, can be hammered into sheets and drawn out into wires. Usually shiny and are

rm a single layer.

of a liquid to a vapour at its boiling temperature.ass in grams.

r= 1 mol dm^-3.

any gas under standard conditions of 1 atm and 298K.

ains the same number of particles as there are atoms in exactly 12g of C-12 which is equal to the relativ

together in giant structures by intermolecular forces as a result of partial ionic character in the covalent

e complete formula of every substance involved in the reaction.

ow many of each atom there are.

ion which is the peak with the highest m/z value.

solution.

lkene, that can be joined to many other small molecules to form a much larger molecule.

ension less than 100 nm.

ts.

-60 molecules. It is harder than diamond. Nanorods are also made from other substances e.g. silicon car

exhibit extraordinary strength and unique electrical properties and are efficient conductors of heat.

curring processes.

iation with crude oil. It is mainly made of methane.

ther living organisms.

icle found in the nucleus of an atom. Mass slightly greater than that of a proton.

als.

he nucleus of an atom-the protons and the neutrons.

sitive ions. An atom of group of atoms that is attracted to a positive charge. A nucleophile is negatively ca reaction, donating electrons.

proportion of branched chain to straight chain alkanes in the fuel mixture.

act they tend to do so in a way which results in an outer shell containing eight electrons.

st likely to be found.

he exception of the simplest compounds such as the oxides and carbonates.

what happens overall to the ions in the reaction.

t.

have if it were totally ionically bonded.


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r substance but is itself reduced.

ning elements with their outer electrons in the p subshell.

ctrons in the p subshell.

lkanes.

^6

ation of a particular group leads to a maximum amount of ir radiation being absorbed. Shown as troughs

lane with bond angles of 120 degrees and one bond at right angles above and one bond at right angles b

of an ir spectrum.lements are a function of their atomic numbers.

ns in the periodic table.

der of their atomic number.

the periodic table.

le.

olecule.

e chemical nature of the element or compound e.g. melting temperature, density, conductivity e.t.c.

e. C=C.

bonding electrons is not evenly distributed.

taking into account any dipole across bonds.

ne monomer units.

ains of smaller units joined together.

r units are joined together to form a long chain polymer molecules.

moved to completion.

of the periodic table after the transition metals.

uracy permitted by the apparatus.

up is attached to a carbon itself bonded to 2 or 3 other hydrogen atoms.

d into useful chemicals.

on atom attached to 2 or 3 hydrogen atoms.

hells which indicates the size of the shell and the distance from the nucleus.

gy content of the universe is constant.

tions.

harge found in the nucleus of an atom.

a pyramid shape.

s using heat in the absence of oxygen.

rolisis from dried biomass.

ts (elements, ions or atoms) that are present in a substance.

of constituents (elements, ions or atoms) that are present in a substance.

stand atomic structure in detail.

l reactions to enable analysis to be carried out.

ucleus breaks up to become more stable and emits alpha, beta or gamma radiation.

ate once living material.

pens.

kes place showing the possible route that a reaction might follow by displaying intermediate stages.

ergy as a function of the progress of a reaction.

uction take place.


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r substance but is itself oxidised.

ined.

1-C4).

ses escaping vapours so they fall back into the reacting flask.

rent isotopes in a sample of an element.

e to an atom of C-12.

are the mass of all atoms to the mass of a standard C-12 isotope.

asses of all the atoms in a chemical formula.t gases have on absorbing ir radiation.

asses of all the atoms in a chemical formula of a covalent compound.

e same outcome.

with high b.p. produced during fractional distillation of crude oil.

m.

h a course of action and reducing them as far as possible.

chloride.

ning elements with their outer electrons in the s subshell.

rons in the s subshell.

cond electron from an atom/ion.up is attached to a carbon itself bonded to 1 hydrogen atom.

on atom attached to 1 hydrogen atom.

concentrated around a nucleus, representing different energy levels of the electrons.

onds and the functional group. Often used for ring compounds.

e when water is added to calcium hydroxide.

solvent at a particular temperature.

uid to form a solution.

, liquid or gas.

to form a solution.

cules in 3d.

a particular substance.

on both sides of an ionic equation and can therefore be left out as they are not involved in the reaction

und breaks down into its elements or reacts with other compounds.

of its atoms in the gaseous state is formed from the element under standard conditions.

of a substance is completely burnt in oxygen under standard conditions.

of the compound is formed from its elements under standard conditions.

of acid is just neutralised by an alkali in their standard states under standard conditions and in solutions

measured under standard conditions.

.

molar volume of gases, 1 atm and 298K.

cal state of a chemical in a reaction.

e constant in spite of ongoing processes which strive to change them.

r formula where the 3d arrangement allows different arrangements in space so the molecules cannot b

ber of atoms in a molecule and the way in which they are arranged relative to each other.

r formula but with the atoms connected together in a different order.

a shell, described by letters such as s, p, d, f, e.t.c.

up of atoms is replaced by a different atom or group of atoms.

tion.


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onoxide which can be used in a number of chemical processes.

ccurring, they have been synthesised in the laboratory.

ystem of measurements.

reaction.

up is attached to a carbon itself bonded to no hydrogen atom.

on atom attached to no hydrogen atoms.

emical reactions.

mes of different solutions which react using an indicator.

ithin the atom as electrons move from one energy level to another.

ents.

y attempt to group the elements.

es/orbitals in the same plane.

share three pairs of electrons.

make up the nucleus are unbalanced and there is an excess of internal energy.

en induced dipoles in adjacent moleculesinto a gas.

ine the concentration of a solution.

nce of an isotope and its RAM.

from a chemical reaction.

oups on the same side of a rigid bond.


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re breaking and new bonds are forming.

e molecular masses of all the products multiplied by 100.

mplete molecules where relevant).


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the heterolytic fission of a covalent bond.

d when it is burnt.

as zeolites are used to reduce the temperature needed for the reactions to take place.

olecules (often isomers of the original molecules). A platinum catalyst is often used to keep the require

solvents.

e the concentration of a known solute in a given solution.

upper atmosphere.


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ld other chemicals.

em and the defined direction is toward the positive charge.

ough a crystal and diffracted by the electrons in the ions or atoms in the structure.

ons.

.t.c.


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changes in concentration of reactants and products.

r of vibrations within the molecule.

roperties of the molecule.

er atoms.

guration because atoms or groups of atoms are attached to either side of a double bond or other rigid bo

ere. Some of the energy is reradiated back to Earth again by these greenhouse gases and this is known a

n dioxide, methane.

ionic equation.

.

tly elsewhere.

nd is broken.

trons.

) substitutes, as the ozone depleting effects are only about 10% of the CFCs.


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atom. This type of force always involves a hydrogen atom and the energy of this attraction is close to tha

ple absorbs each wavelength.

ns together.

mplete outer shell of electrons.

he reaction does not take place.

nt of energy required to separate a solid ionic compound into gaseous ions.


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s the most hydrogen atoms attached to it.

the isotopes in a sample of an element.

olids at room temperature except for mercury.

e atomic or molecular mass of a substance in grams.

bond.

ide.

arged or contains a lone pair of electrons.


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on the ir spectrum.

elow the plane.


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.

containing 1 mol dm^-3.

superimposed upon each other.


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to a minimum.


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nd.

s the greenhouse effect.


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t of weak covalent bonds (155 kJ/mol).

as chemistry glossary

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