Subject Specific Language: Chemistry
Key word / term / Definition /A measurement is considered accurate if it is judged to be close to the true value.
When dissolved in water, it solution has a pH value less than 7. Acids are proton (H+ ion) donors.
The minimum amount of energy needed for a reaction to start / take place.
Any element in Group 1 of the periodic table.
A solution which has a pH value more than 7, usually produces hydroxide ions (OH-).
A saturated hydrocarbon with the general formula CnH2n+2,
e.g. methane, ethane, and propane.
An unsaturated hydrocarbon which contains a double bond between two carbon atoms.
Its general formula is CnH2n, e.g. ethene, C2H4.
A mixture of two or more elements, at least one of which is a metal, e.g. steel
Describes a substance that does not contain water.
The positive electrode in electrolysis.
Results that do not match the pattern seen in the other data collected, or those that are well outside the range of other repeat readings (outliers).
The mixture made by adding a soluble substance to water.
The relatively thin layer of gases that surround planet Earth.
The smallest part of an element that can still be recognised as that element.
A measure of the amount of starting materials that end up as useful products.
The number of protons (which equals the number of electrons) in an atom. It is sometimes called the proton number.
The number of atoms, molecules, or ions in a mole of any substance (i.e., 6.02 × 1023 per mol).
A symbol equation in which there are equal numbers of each type of atom on either side of the equation.
The oxide, hydroxide, or carbonate of a metal that will react with an acid, forming a salt as one of the products. (If a base dissolves in water it is called an alkali). Bases are proton (H+ ion) acceptors.
Materials that can be broken down by microorganisms.
Any fuel taken from living or recently living materials, such as animal waste.
The huge reaction vessels used in industry to extract iron from its ore.
The energy required to break a specific chemical bond. Also the amount of energy stored within a specific chemical bond.
A long glass tube with a tap at one end and markings to show volumes of liquid; used in titrations to add precisely known volumes of liquids to a solution in a conical flask below it.
The total amount of carbon dioxide and other greenhouse gases emitted over the full life cycle of a product, service or event. Also used to describe the amount of carbon dioxide and other greenhouse gases produced by the life style of an individual.
An alloy of iron containing controlled, small amounts of carbon.
Categoric variables have values that are labels. For example: types of material, colours of clothing, names in a class.
A substance that speeds up a chemical reaction by providing a different pathway for the reaction that has a lower activation energy. The catalyst is chemically unchanged at the end of the reaction.
A device fitted to exhausts of vehicles to reduce pollutants released, by speeding up reactions with oxygen.
The negative electrode in electrolysis.
Materials made by heating clay, or other compounds, to high temperatures (called firing) to make hard, but often brittle, materials, which make excellent electrical insulators.
The process whereby small amounts of dissolved substances are separated by running a solvent along a material such as absorbent paper.
The change in global weather patterns and temperatures that could be caused by excess levels of greenhouse gases in the atmosphere.
A system in which no matter enters or leaves.
An explanation of chemical reactions in terms of reacting particles colliding with sufficient energy for a reaction to take place.
Materials made of two or more different materials, containing a matrix or binder surrounding and binding together fibres or fragments of another material which acts as the reinforcement.
A substance made when two or more different elements are chemically bonded together.
When a fuel burns in excess oxygen, producing carbon dioxide as a product.
A solution which contains a low volume of water compared to the solute. The more concentrated, the less waster present.
Can have values (called a quantity) that can be given by measurement, for example: mass, volume, temperature, etc.
Data that can take any value, or be further divided depending on resolution. E.g. 1, 1.0, 1.02, 1.015
If an experiment is to determine the effect of changing a single variable, a control is often set up in which the independent variable is not changed, therefore enabling a comparison to be made.
If the investigation is of the survey type a control group is usually established to serve the same purpose.
A variable which may, in addition to the independent variable, affect the outcome of the investigation and therefore must be kept constant, or if it cannot be kept constant, must be monitored.
The bond between two (non-metal) atoms that share one or more pairs of electrons.
The attraction between two (non-metal) atoms that share one or more pairs of electrons.
The reaction used in the oil industry to break down large hydrocarbon chains into smaller, more useful ones.
Information, either qualitative or quantitative, that has been collected.
A bonding electron that is no longer associated with any one particular atom, so is free to move between different atoms.
The variable for which the value is measured for each and every change in the independent variable. (The one you’re measuring)
The automatic mixing / spreading of liquids and gases due to the random (Brownian) motion of their particles.
A solution containing a high volume of water compared to the solute.
A graph will show direct proportionality if the line of best fit is a straight line and passes through the origin.
Data that can only take certain values, similar to categoric data.
A reaction in which a more reactive element takes the place of a less reactive element in one of its compounds or in solution.
e.g. magnesium + copper oxide è magnesium oxide + copper
The separation of a liquid from a mixture by evaporation followed by condensation.
A drawing to show the arrangement of the outer shell electrons only, in the atoms or ions in a substance.
A large organic molecule that encodes genetic instructions for the development and functioning of living organisms and viruses.
A covalent bond made by the sharing of two pairs of electrons.
Contain chemicals that react to produce electricity, e.g. a car battery.
The breakdown of a substance containing ions using electricity.
A liquid, containing free-moving ions, which is broken down by electricity in the process of electrolysis.
A subatomic particle with a negative charge. Electrons orbit the nucleus of atoms or ions in shells.
A set of numbers to show the arrangement of electrons in their shells (or energy levels).
A substance made up of only one type of atom. An element cannot be broken down chemically into any simpler substance.
The point in a titration where the reaction is complete and titration should stop.
A reaction that takes in energy from the surroundings.
A formula showing the ratio of atom types within a substance. It does not provide the actual chemical formula.
The point in a reversible reaction at which the forward and backward rates of reaction are the same. Therefore, the amounts of substances present in the reacting mixture remain constant.
A reaction that transfers energy to the surroundings.
A fair test is one in which only the independent variable has been allowed to affect the dependent variable. All other variables are controlled.
The reaction in which the enzymes in yeast turn glucose into ethanol and carbon dioxide.
The technique used to separate substances that are insoluble in a particular solvent from those that are soluble.
A method of instrumental analysis in which the light given off when a sample is placed in a flame produces characteristic line spectra to identify and measure the concentration of metal ions in the sample.
A substance that is easily ignited and capable of burning rapidly.
A mixture that has been designed as a useful product.
Hydrocarbons with similar boiling points separated from crude oil.
A way to separate liquids from a mixture of liquids by boiling off the substances at different temperatures, then condensing and collecting the liquids.
Sources of electricity that are supplied by an external source of fuel.
An allotrope (form) of the element carbon that can exist as large cage-like structures, based on hexagonal rings of carbon atoms.
An atom or group of atoms that give organic compounds their characteristic properties / reactions.
Iron or steel objects that have been protected from rusting by a thin layer of zinc metal at their surface.
A huge 3D network of covalently bonded atoms, e.g. diamond.
A huge 3D network of atoms or ions, e.g. sodium chloride.
See Giant lattice.
Change of the quantity plotted on the y-axis, divided by the change in the quantity plotted on the x-axis.
All the elements in the columns (labelled 1 to 7 and 0) in the periodic table.
An equation that describes oxidation (loss of electrons) or reduction (gain of electrons).
The elements found in Group 7 of the periodic table.
A hazard is something (e.g., an object, a property of a substance or an activity) that can cause harm.
A group of related organic compounds that have the same functional group.
Describes a substance that contains water in its crystals.
A compound containing only hydrogen and carbon.
A proposal intended to explain certain facts or observations.
When a fuel burns in insufficient oxygen, producing carbon monoxide as a toxic product.
The variable for which values are changed or selected by the investigator. (The one you’re changing).
Unreactive.
The attraction / attractive forces between the individual molecules in a covalently bonded substance.
The attraction / attractive forces between individual atoms or ions in a molecule.
A charged particle produced by the loss or gain of electron(s).
The electrostatic force of attraction between positively and negatively charged ions.
An equation that shows only those ions or atoms that change in a chemical reaction.
Atoms that have the same number of protons but different number of neutrons, i.e., they have the same atomic number but different mass numbers.
The total mass of the products formed in a reaction is equal to the total mass of the reactants.
When a change in conditions is introduced to a system at equilibrium, the position of equilibrium shifts so as to cancel out the change.
A process carried out to assess the environmental impact of products, processes or services at different stages in their life cycle.
Used when both variables are continuous. The line should normally be a line of best fit, and may be straight or a smooth curve.
A straight line that represents the general trend of data. An equal number of data points should be above and below the line of best fit.
The number of protons and neutrons in the nucleus of an atom. Mass = protons + neutrons
The arithmetical average of a series of numbers (add together all valid results and divide by the number of results)
When some elements or compounds are mixed together and intermingle but do not react together (i.e. no new substance is made). A mixture is not a pure substance. Substances within a mixture can be separated without the need for a chemical reaction.
The amount of substance in the relative atomic or formula mass of a substance in grams. E.g. 1 mole of oxygen atoms = 16g, 1 mole of water molecules = 18g
The chemical formula that shows the actual numbers of atoms in a particle molecule.
Small reactive molecules that react together in repeating sequences to form a very large molecule (a polymer).
The study of very tiny particles or structures between 1 and 100 nanometres in size – where 1 nanometre = 10–9 metres.
A solution with a pH value of 7 which is neither acidic nor alkaline. Alternatively, something that carries no overall electrical charge.
The chemical reaction of an acid with a base in which a salt and water are formed. If the base is a carbonate or hydrogen carbonate, carbon dioxide is also produced in the reaction.
Uncharged particles of the same mass as protons. The nucleus of an atom consists of protons and neutrons.
The very unreactive gases found in Group 0 of the periodic table. Their atoms have very stable electronic structures.
Something which cannot be replaced once it is used up.
The very small and dense central part of an atom that contains protons and neutrons.
A comparison of the size of values. Two values are the same order of magnitude if their difference in size is small in comparison to other values being compared.
Ore is a rock which contains enough metal to make it economically worthwhile to extract the metal.
The reaction when oxygen is added to a substance / or when electrons are lost.
Describes a substance that has had oxygen added to it / or has lost electrons.
A Small solid particle given off from motor vehicles as a result of incomplete combustion of its fuel.
The actual mass of product collected in a reaction divided by the maximum mass that could have been formed in theory, multiplied by 100.
An arrangement of elements in the order of their atomic numbers, forming groups and periods.
A number which shows how strongly acidic or alkaline a solution is.
A glass tube used to measure accurate volumes of liquids.