Question | Answer |
accuracy | closeness to the true value |
acid | substance or solution which shows properties characteristic of the presence of hydrogen ions e.g.turns moist litmus red, sour taste |
acidity | extent of acid properties |
activation energy | energy needed to begin a chemical reaction |
addition polymer | polymer formed by adding together of monomer molecules containing C=C |
alkane | hydrocarbon with general formula CnH2n+2 |
alkanol | molecule saturated with hydrogen like an alkane and containing an alcohol functional group –OH; general formula CnH2n+1OH |
alkene | hydrocarbon with general formula CnH2n |
allotropes | different physical forms of an element |
alloy | mixture of metal with other element(s) that are usually metal(s) |
amphiprotic | ionic or molecular species which can act both as an acid by donating protons and a base by accepting protons |
anaerobic | without oxygen or air |
analyse | identify components and the relationship between them; draw out and relate implications |
anionic | negatively charged |
anode | electrode at which oxidation occurs |
antifreeze | chemical added to water to lower its freezing point |
apply | use in a particular situation |
aq | phase descriptor for aqueous solution |
aqueous solution | solution with water as the solvent |
Arrhenius theory of acids and bases | acid produces hydrogen ions in water while a base produces hydroxide ions in water |
artefact | object made by human hand |
assess | make a judgement of value, quality, outcomes, results or size |
atmosphere | layer of gas around the Earth |
atomic absorption spectroscopy | AAS; a technique able to measure the amount of element present in ppm or ppb |
atomic number | number of protons in the nucleus of an atom; unique number for each element |
atomic radius | radius of an atom usually measured in picometres (10-12 m) |
atomic structure | arrangement of protons and neutrons in a nucleus surrounded by electrons in shells |
Avogadro’s law | equal volumes of gases, at the same conditions of temperature and pressure, contain the same number of molecules |
balanced formulae equation | chemical reactions expressed in formulas and balanced so that there is the same number of each type of atom on reactants side and products side e.g. 2H2 + O2 --> 2H2O |
base | substance or solution which shows properties characteristic of the presence of hydroxide ions e.g.turns moist litmus blue, slippery feel |
basicity | extent of base properties |
biomass | organic matter produced by photosynthesis; mostly cellulose |
biopolymer | naturally occurring polymer produced using renewable resources like micro-organisms or plants |
biosphere | parts of the Earth where life is found |
boiling point | temperature at which liquid rapidly changes with bubble formation to gas |
bond | attraction |
bond-breaking | energy absorbing process in which atoms, ions or molecules are broken apart |
bond-making | energy releasing process in which atoms, ions or molecules come together forming a bond |
brass | alloy of copper and zinc |
brine | concentrated salt solution |
Bronsted-Lowry theory | acids are proton donors, bases are proton acceptors |
Bronze Age | Age between Stone Age and Iron Age when the most valued tools and weapons were made of bronze |
buffer | mixture of a weak acid and its conjugate base able to resist change in pH |
button cell | galvanic cell shaped like a button |
calculate | determine from given facts, figures or information |
calorimetry | measurement of heat change |
carbohydrate | compounds containing carbon, hydrogen and oxygen with the hydrogen:oxygen ratio the same as in water |
carbon-12 | isotope of carbon containing six protons and six neutrons in the nucleus |
carboxylic acid | acid containing a carboxylic functional group –COOH |
carboxylic acids | acids that contain the –COOH functional group |
catalyst | substance which speeds up a chemical reaction and remains unchanged at the end of the reaction |
catchment | area from which something comes; a water catchment is land bound by hills or mountains from which surface or ground water flows |
cathode | electrode at which reduction occurs |
cationic | postitively charged |
chemical change | change in a substance that involves rearrangement of particles into new combinations; at least one new substance produced |
chemical property | property of a substance reacting with another chemical |
chlorofluorocarbon | CFC; compound of chlorine, fluorine and carbon only |
chronology | order of past events in time |
collaboration | working together effectively |
collating information | comparing different sources in order to note points of agreement and disagreement |
combining power (valency) | predictor of how many of an atom will combine with atoms of other elements; determined by the number of electrons in the outer shell of the atom |
combustion | exothermic chemical reaction in which a chemical reacts with oxygen, always releasing heat and often light |
compare | show how things are similar or different |
complete combustion | combustion in which all reacting elements react fully with oxygen e.g. complete combustion of a hydrocarbon produces carbon dioxide and water |
compound | pure substance containing two or more elements combined in a fixed ratio of mass and particles |
concentrated | solution containing a large amount of solute in the solvent |
concentration | a measure of the quantity of dissolved substance in a stated quantity of solution |
condensation polymer | polymer formed by monomer molecules condensing out a small molecule such as water |
conductivity | ability to allow passage of electricity/heat |
conjugate acid | acid formed by addition of H+ to a base |
conjugate base | base formed by removal of H+ from an acid |
conservation | the act of saving or preserving |
coordinate covalent bond | covalent bond where the shared pair of electrons come from only one of the atoms joined |
corrosion | deterioration of any material or its properties because of chemical reaction with its environment |
covalent | involves sharing of electrons between atoms |
covalent bond | force of attraction between two atoms formed by sharing of a pair of electrons; a single covalent bond = 1 pair, a double covalent bond = 2 pairs, a triple covalent bond = 3 pairs of electrons |
covalent compound | compound made up of atoms joined by covalent bonds |
covalent lattice | related to extensive three-dimensional structures of atoms joined by covalent bonds; covalent network |
covalent molecular | related to small molecules |
covalent network | related to extensive three-dimensional structures of atomsjoined by covalent bonds; covalent lattice |
data | facts or figures that can be used to draw conclusions |
data logger | device for storing data |
decarbonate | removal of carbon dioxide from a solution or a solid |
decomposition | reaction in which one substance forms two or more substances |
dehydrating agent | chemical which removes water from other chemicals |
dehydration | loss of water |
density | density = mass / volume |
describe | provide characteristics and features |
design | provide the steps for an experiment, procedure or investigation |
destructive testing | testing of a material that changes its properties |
detergent | cleaning agent with surface active properties |
diaphragm process | process in which a diaphragm separates hydrogen gas and chlorine gas produced in the electrolysis of concentrated salt solution to sodium hydroxide solution |
dilute | solution containing a small amount of solute in the solvent |
dipole-dipole forces | attractive forces between polar molecules |
discuss | identify issues and provide points for and/or against |
dispersion forces | forces of attraction that occur between all molecules |
dissolution | dissolving |
dissolved oxygen | DO; amount of dissolved oxygen in a water sample |
Eø | electrical potential |
electrode | metal or graphite which transfers electrons to or from an electrolyte |
electrolysis | chemical reaction requiring electrical energy |
electrolyte | liquid substance or solution through which ions can move |
electrolytic cell | arrangement of chemicals in which electrical energy can be used to produce new chemicals |
electron configuration | arrangement of electrons in an atom e.g. 2.4 for carbon shows there are 2 electrons in the energy level closest to the nucleus and 4 electrons in the next |
electronegativity | ability of a neutral atom to attract extra electrons (low for metals, high for non-metals) |
element | pure substance consisting entirely of atoms with the same positive nuclear charge (that is the same atomic number) |
empirical formula | formula giving the simplest whole number ratio of particles in a compound |
emulsifier | surface active agent that stabilises an emulsion |
emulsion | dispersion of one liquid in another liquid |
endothermic | change or reaction which absorbs heat |
energy profile diagram | graph showing change in the total amount of energy in all the chemicals as a reaction goes from reactants to products |
energy transfer | movement of the same sort of energy between objects or locations |
energy transformation | change from one form of energy to another e.g. chemical to heat |
equilibrium | situation in a reversible reaction in a closed system where the rate of forward reaction equals the rate of reverse reaction |
equilibrium constant | numerical value calculated for a particular equilibrium equation at a fixed temperature; symbol K |
equivalence point | point in a titration at which the reactants have completely reacted together in the ratio of mole quantities given in the balanced equation for the reaction |
ethical | following rules or standards for right conduct or practice |
eutrophication | excessive growth of organisms followed by decay and depletion of oxygen concentration resulting from increase in nutrient content of a body of water |
evaluate | make a judgement based on criteria; determine the value of |
exothermic | change or reaction which releases heat energy |
explain | relate cause and effect |
explosion | rapid release of energy and/or matter |
explosive combustion | combustion that rapidly releases heat and gases causing an explosion |
explosive combustion | combustion that rapidly releases heat and gases causing an explosion |
fermentation | controlled chemical change catalysed by enzymes from organisms such as yeast |
first ionisation energy | energy required to remove a single electron from a gaseous atom; usually measured in kJ per mole of atoms |
fossil fuel | fuel, such as coal, petroleum or natural gas, formed from the remains of past life on Earth |
fractional distillation | distillation of a mixture of liquids into fractions of different boiling point ranges |
free radical | atom or molecule with unpaired electron(s) |
fuel cell | cell releasing electrical energy in which a flow of fuel is oxidised without burning |
functional group | distinctive reactive part of an organic molecule e.g. in alkenes the functional group is C=C |
galvanic cell | arrangement of chemicals capable of releasing electrical energy from chemical energy; commonly called a battery |
gravimetric analysis | quantitative analysis using weighing |
group | vertical column of the Periodic Table |
habitat | locality where organism(s) live |
haloalkane | saturated hydrocarbon containing at least one halogen atom per molecule |
halon | bromine containing compound which can cause breakdown of ozone in the atmosphere |
hardness (of solid) | ability to resist applied pressure |
hardness (of water) | degree to which water is hard to lather with soap |
heat of combustion | heat change when a substance is combusted |
heavy metal | metal with a density above 5 g cm-3; most of these metals are poisonous |
homologous series | series of chemicals with the same functional group that show a gradual change in properties |
hydrogen bonding | bonding between the hydrogen attached to a nitrogen, oxygen or fluorine atom and a nitrogen, oxygen or fluorine atom in a nearby molecule |
hydrosphere | layer of water around the Earth including fresh water and salt water |
hydrothermal vent | opening in the ocean floor out of which hot water containing dissolved minerals passes |
identify | recognise and name |
ignition temperature | temperature at which a substance in contact with air starts to burn |
incomplete combustion | combustion in which at least some reacting elements do not react fully with oxygen e.g. incomplete combustion of a hydrocarbon producing carbon monoxide or carbon rather than carbon dioxide |
indicator | substance that changes (usually in colour) when there is a change in the chemical nature of a system; an acid-base indicator changes colour according to pH |
information | meaningful data; data that has been processed so that it takes on meaning |
intermolecular forces | forces of attraction between molecules – dispersion forces between all molecules, dipole-dipole forces between polar molecules, hydrogen bonding between molecules with a hydrogen bonded to a nitrogen, oxygen or fluorine atom |
ion | charged particle formed from an atom of group of atoms (polyatomic ion) |
ionic | caused by charged particles (ions) |
ionic compound | compound made up of ions; solid compound that does not conduct electricity when solid but conducts electricity when liquid as the ions can move |
ionic equation | equation in symbols involving at least one ion |
ionisation | formation of an ion or ions as when an acid molecule releases a hydrogen ion and forms a negative ion |
Iron Age | Age between Bronze Age and the modern era when most valued implements were made of iron |
isomers | different structural forms of the same molecular formula |
isotopes | atoms of the same element; atoms wtih the same number of protons in the nucleus |
IUPAC | International Union of Pure and Applied Chemistry |
justify | support an argument or conclusion |
kinetic energy | energy due to motion |
kPa | kiloPascal; unit of pressure |
lattice | arrangement of particles in a crystal |
leaching | process in which soluble components, e.g. salt, are removed from insoluble material, e.g. soil, by the action of a solvent, e.g. water |
Lewis electron dot structure | diagram showing number of electrons in the outer main energy level of an atom |
limitation | that which limits something |
lithosphere | relatively rigid and cool outside rock layer of the Earth consisting of the crust and the outermost layer of the mantle |
malleability | ability to be shaped without breaking |
management | handling, direction and control of a situation |
mass number | total number of protons and neutrons in the nucleus of an atom |
mass ratio | ratio of masses of pure substances reacting or produced in a chemical reaction (mass ratio of elements reacting is used, together with a knowledge of atomic masses, to calculate the empirical formula of the resulting compound) |
melting point | temperature at which a solid changes to liquid |
membrane process | process in which a membrane that water and anions cannot pass through is used to produce sodium hydroxide solution containing hardly any salt from the electrolysis of salt solution |
mercury process | process in which a mercury cathode in concentrated salt solution forms a sodium amalgam that is reacted with water to form high purity sodium hydroxide |
metabolism | all chemical reactions in a cell, part of or complete organism |
metal | chemical element that is malleable, has a lustre and is a good conductor of heat and electricity; three-dimensional lattice of ions in a sea of electrons |
micro-technique | method using small quantities |
mid-ocean ridge | volcanically active underocean region where crustal plates are diverging |
mineral | useful element or compound from the Earth |
mixture | mix of pure substances that may be separated by physical or mechanical methods; properties vary according to the parts and their proportions |
molarity | moles of solute per litre of solution |
mole | large number ( 6x1023) of particles; defined as the number of atoms in exactly 12g of carbon-12 |
mole ratios | the relative number of moles reacting and produced in a chemical reaction e.g. in 2H2 + O2 --> 2H2O the mole ratio is 2:1-->2 |
molecular formula | chemical formula showing the actual number of each type of atom in a molecule |
molecular shape | the overall form, outline or external surface of a molecule |
molecular structure | the arrangement of atoms within a molecule |
molecules | neutral particles which can move independently of each other; all molecules consist of two or more atoms joined together except for the noble gases whose molecules consist of a single atom |
monitoring | checking, observing or recording a situation; testing program to assess potential changes |
monomer | compound with small molecules able to join together to form a long chain polymer molecule |
natural product | extract from a natural product, typically a compound rather than an element |
net ionic equation | chemical equation in which the ions that are ‘spectators’ and do not react are left out as they are not part of the reaction e.g. OH– + H+ --> H2O |
neutral | between acid and base; having neither acidic nor basic properties |
neutralisation | reaction between an acid and a base to form a salt and water |
noble gas | very unreactive monatomic elements in the last group of the Periodic Table |
non-destructive testing | testing of a material that does not change its properties |
non-ionic | no ionic charge but often polar (always polar in the case of non-ionic detergents) |
non-metal | chemical element not possessing the properties of metals |
non-polar | without electric poles; used to describe molecules which do not have a positive and a negative end |
non-renewable resource | resource, such as copper ore or coal, which once used up is not replaced or replaced too slowly by natural processes |
normal atmospheric pressure | 100 kPa |
order of magnitude | quantity expressed to the nearest power of ten e.g. 256 has an order of magnitude of 102 |
ore | metal bearing substance, e.g. rock, from the Earth with a commercial value |
outline | indicate the main features of |
oxidation | loss of electron(s) in a reaction |
oxidising agent | abbreviation: oxidant; chemical which causes oxidation - loss of electrons - by another chemical |
passivating metal | metal coated with a tenacious oxide layer that protects and results in less metal activity than expected |
period | horizontal row of the Periodic Table |
Periodic Table | Arrangement of chemical elements so that elements with similar properties occur at fixed intervals |
periodicity | tendency to recur regularly |
petrochemical | chemical made from compounds in petroleum or natural gas |
pH | –log10[H+] |
pH meter | millivoltmeter with scale marked in pH units that can be connected to a pH probe |
pH probe | pH sensitive electrode system |
photosynthesis | process in which green plants use light energy to make carbohydrates from carbon dioxide and water |
physical change | change in a substance that does not involve rearrangement of particles into new combinations; no new substance produced |
physical property | property of a substance measured by itself |
polar molecule | molecule with electric poles δ+ and δ– so that a particular end of the molecule is attracted to a charge; a polar molecule is said to have a dipole |
pollution | contamination by unwanted substances or energy |
polymer | long chain molecule formed by joining monomer molecules |
ppb | parts per billion |
ppm | parts per million |
precipitate | solid material which separates from solution when solutions are mixed |
precipitation | falling out of a solid from solution when solutions are mixed |
predict | suggest what may happen based on available information |
primary alkanol | alkanol with the OH group on an end carbon atom |
product | chemical produced in a chemical reaction |
propose | put forward for consideration or action |
qualitative | concerned with features, characteristics or properties described without using numbers e.g. colour, feel, smell |
qualitative analysis | finding out what is present in a sample |
quantitative | concerned with amount |
quantitative analysis | finding how much is present in a sample |
radioactive | capable of emitting particles and energy from nuclei |
radioisotope | radioactive isotope |
rate | rate of reaction measured as change in concentration with time |
reactant | chemical reacting in a chemical reaction |
reactivity | tendency to undergo chemical reaction |
recycle | reuse of waste material |
redox | abbreviation of reduction-oxidation |
reducing agent | abbreviation: reductant; chemical which causes reduction - gain of electrons - by another chemical |
reduction | gain of electrons during a reaction |
reflux / refluxing | process of boiling liquid in a flask with a condenser attached so that vapours are condensed and returned to the liquid |
relate | provide some connection or relation to |
reliability | trustworthiness; degree to which repeated observations and/or measurements, taken under identical circumstances, will yield the same results |
renewable | resource that can be used then reformed from its products by the input of solar energy |
restoration | the act of bringing back to original condition |
risk assessment | procedure involving identification of a hazard then judgement and control of possible harm from the hazard |
sanitise | make disease free |
saponification | soap formation |
saturated dissolution | saturated solution in contact with undissolved solid |
semi-metal | element intermediate in properties between metals and non-metals |
sensor | sensitive part e.g. glass electrode of a pH meter |
slow combustion | slow reaction with oxygen |
solder | alloy usually of lead and tin |
solute | substance that dissolves |
solution | mixture of solute and solvent |
Solvay process | process for producing sodium carbonate from soidum chloride and calcium carbonate by using recycled ammonia |
solvent | liquid able to dissolve another substance |
specific heat (capacity) | number of joules of heat energy required to raise the temperature of one kilogram by one kelvin; C measured in J kg-1 K-1 |
spontaneous combustion | slow combustion where the heat released cannot escape easily and the temperature rises until the ignition temperature is reached and fast combustion starts |
standard solution | solution of accurately known concentration and composition |
steel | alloy of iron and carbon |
stoichiometry | quantitative relationships in chemical reactions |
straight-chained | chain of carbon atoms without branching |
strong acid | an acid that is completely ionised in solution |
strong base | a base that is completely ionised in solution |
sulfate reducing bacteria | abbreviation SRB; anaerobic bacteria that reduce sulfate ions to hydrogen sulfide |
surface tension | energy required to increase the surface area of a liquid caused by attractive forces between molecules of the liquid |
synthesis | building up a substance from simpler substances |
synthetic product | product synthesised from simple chemicals |
systematic name | name from which the structure or formula of a chemical may be deduced |
terrestrial | land-based |
thermal pollution | addition of heat to an environment causing unwanted or harmful effects |
titration | technique in which a solution of unknown concentration is reacted with a solution of known concentration (a standard solution) until equivalence point is reached |
transuranic | element with atomic number above 92, beyond uranium |
turbidity | opaqueness or cloudiness of water |
uncertainty | of a measurement is half the quantity it was measured to e.g. a measurement made to the nearest gram has an uncertainty of ± 0.5 g |
validate | to make just, sound or well-founded |
validity | the extent to which processes and resulting data measure what was intended |
vanadium redox cell | cell developed at University of NSW in which solutions of vanadium(V) and vanadium(II) react releasing electrical energy |
viscosity | resistance of a liquid to flow |
volatility | measure of how readily a liquid changes to vapour |
weak acid | acid that is little ionised in solution |
weak base | base that is little ionised in solution |
weathering | any chemical or mechanical action of the atmosphere on rocks changing their colour, texture or chemical composition |
word equation | chemical reaction expressed in words e.g. hydrogen + oxygen --> water |