AQA GCSE Triple Science

Activation energy

the minimum amount of energy required for a reaction to take place

Addition polymerisation

when many monomers join together to form a large molecule

Addition reaction

a reaction in which the reactants join together to form one product

Agriculture

farming

Algae

small green aquatic plants

Alkali metals

elements in group 1 of the periodic table

Alkanes

saturated hydrocarbons with the general formula CNH2N +2

Alkenes

unsaturated hydrocarbons with the general formula CNH2N

Alloy

a mixture that contains at least one metal

Amino acid

a simple organic compound containing both the carboxyl and an amino group

Anode

a positively charged electrode

Aqueous

dissolved in water

Atom

the smallest part of an element that can exist

Atom economy

a measure of the amount of reactant converted to a useful product

Atomic number

The number of protons in the nucleus of an atom

Avogadro constant

The number of particles in one mole of any substance i.e. 600,000 billion billion or 6.02×10 to the 23

Biased

Has a prejudice is not a balanced view

Billion

1000000000 or 1000 million

Bioleaching

The use of bacteria to extract metals from low-grade ores

Boiling point

The specific temperature at which a pure substance changes state from liquid to gas and from gas to liquid

brittle

Breaks easily when hit

Carbon footprint

The total amount of carbon dioxide and other greenhouse gases that are emitted of the full life-cycle of a product or service or an event

Carboxyl

the -COOH Group found in carboxylic acids

Catalyst

a substance that speeds up the rate of a chemical reaction but is not used up in the reaction itself

Cathode

a negatively charged electrode

Cell (electrical)

contains chemicals that react together to release electricity

cellulose

a form of carbohydrate

Chromatography

A separation technique used to separate the coloured components of mixtures

Closed system

When nothing can enter or leave

Combustion

Burning

Composite material

A material consisting of two materials with different properties which are combined together to produce an improved material with its own properties that are better than either of the individual components properties

Compound

A substance containing atoms of two or more elements which are chemically combined in fixed proportions

Concentration

The amount of substance in a given volume normally measured in units of mol/dm3

Condensation polymerisation

When many small monomer molecules joined together to form a large polymer molecules and small molecules such as water

Conservation of mass

The total mass of the products of a chemical reaction is always equal to the total mass of the reactants

Corrosion

When a metal reacts with oxygen and water

Covalent bond

A shared pair of electrons between atoms in a molecule

Cracking

The process by which a longer chain hydrocarbons can be broken down into shorter more useful hydrocarbons

Crude oil

A fossil fuel a mixture consisting mainly of alkanes

Cryolite

A compound of aluminium

Crystallisation

Technique used to obtain a soluble solid from a solution

delocalised

Not bound to one atom

desalinated

Salt water that has had all the dissolved salts removed to make pure water

Diamond

A form of carbon with a giant covalent structure that is very hard

Dicarboxylic acid

A molecule with two carboxyl -COOH groups

diol

a molecule with two hydroxyl -OH groups

Displace

To take the place of another element in a reaction

Displacement reaction

A reaction in which a more reactive metal displaces a less reactive metal from a solution of it salt

Dissociate

To split up into ions

DNA

A very large molecule with a double helix structure which stores and transmits instructions for the development of living organisms and and some viruses

Ductile

Can be drawn into a wire

Electrode

An electrical conductor used in a cell

Electrolysis

The process by which an ionic compound is broken down into its elements using an electrical current

Electrolyte

The substance being broken down during

Electron

A super atomic particle with a relative mass that is very small and the relative charge of -1

Electron configuration

Represents how do you electrons are arranged in shells around the nucleus of an atom

Electrostatic

A force of attraction between oppositely charged species

Element

A substance made of only one type of atom

Endothermic reaction

A reaction that takes in energy from the surroundings

Energy level diagram

A diagram showing the relative energies of the reactants and products of the reaction the activation energy and overall energy change of the reaction

Equation

A scientific statement that uses chemical names or symbols to sum up what happens in a chemical reaction

Equilibrium

When the rate of forward reaction is equal to the rate of backward reaction

exothermic reaction

a reaction that gives out energy to the surroundings

extraction

the process of obtaining / taking out / removing

fermentation

a chemical reaction in which alcohol and carbon dioxide are produced from glucose

filtration

separation techniques used to separate insoluble solids from soluble solids

Flame emission spectroscopy

an instrumental method of analysis, which is used to identify the metal ions in a solution and measure their concentration

flame tests

a way of identifying metal ions from the colour produced when the metal compound is heated in a flame

formulation

a mixture that has been carefully designed to have specific properties

fractional distillation

a separation technique used to separate mixtures which contain components with similar boiling points

fresh water

water that contains low levels of dissolved salts

fuel cell

a very efficient way of producing electrical energy in which a fuel is oxidised electrochemically to produce a potential difference or voltage

fullerene

a form of carbon in which the carbon atoms are joined together to form hollow structures

galvanising

a method of protecting iron or steel objects by covering them in a coating of zinc

gradient

gradient=difference in the y axis value / difference in the x axis value

graphene

a form of carbon a single layer of graphite just one atom thick

graphite

a form of carbon with a giant covalent structure that conducts electricity

greenhouse gases

gases that when present in the atmosphere absorb the outgoing infrared radiation increasing the earths temperature

haber process

an industrial process used to manufacture ammonia

half equation

used to show what happens to one of the reactants in a chemical reaction

halide

a halogen ion

halogens

elements in group 7 of the periodic table

homologous series

members of the same family of compounds they have the same functional group and each one differs from the previous one by the addition of CH2

hydration

a reaction in which H2O is added to a substance

hydrocarbon

a molecule that contains only carbon and hydrogen atoms

hydroxyl

the -OH group found in alcohols

indicator

a chemical that is one colour in an acid and another colour in an alkali

infrared

a type of radiation that is part of the electromagnetic spectrum

insoluble

a substance that does not dissolve in a solvent

intermolecular

between molecules

ion

atoms that have gained or lost electrons and now have an overall charge

ionic bond

the force of attraction between positive and negative ions

ionic equation

a simplified version of a chemical equation which just shows the species that are involved in the reaction

ionised

split up into ions

isotope

atoms of the same element that have the same atomic number but a different mass number

Le Chatelier's Principle

a rule that can predict the effect of changing conditions on a system that is in equilibrium

life cycle assessment

used to assess the environmental impact a product over its whole lifetime

limiting reactant

the reactant that is completely used up in a reaction it stops the reaction from going any further and any further products being produced

malleable

can be hammered into shape

mass number

the total number of protons and neutrons in the nucleus of an atom