Section 2 f) Key Words

Galvanising: Coating iron in zinc as a form of sacrificial protection.

Oxidation: Gain of oxygen ions.

Reactivity series: The order in which metals will react with a non-metal, more reactive metals displacing less reactive metals.

Reduction: Loss of oxygen ions.

Rust: Compound formed when iron reacts with water and oxygen.

Sacrificial protection: Coating a less reactive metal in a more reactive metal, so the more reactive metal reacts with the surroundings and the less reactive metal is protected.

Section 2 e) Key Words

Chemical Test: A test involving the chemical molecules, and the way they react with other molecules. e.g. test for water using anhydrous copper (ii) sulphate.

Combustion: Reaction with oxygen that produces a flame (a lot of heat and light energy is released)

Physical Test: A test involving the physical properties of a molecule, e.g. boiling point of water.

Section 2 b) Key Words

Electrostatic attraction: Attraction between two charged particles, e.g. nuclei and electrons

Group 1: The first group of the periodic table. Each element has 1 valence electron and is extremely reactive. Examples include lithium, sodium, potassium, caesium, francium

Lithium: Li, the least reactive group 1 element. Has two shells of electrons, 3 protons, and a relative atomic mass of 7.

Potassium: K, the third element of group 1. Has four shells of electrons, 19 protons and a relative atomic mass of 39.

Sodium: Na, the second element of group 1. Has three shells of electrons, 11 protons and a relative atomic mass of 23.

Valence electrons: Outer shell electrons.

Section 2 a) Key Words

Acid: A substance with a low pH (less than 7). The lower the pH, the more acidic (due to more H+ ions). Can neutralise bases and form salts.

Alkali metals: Metals in group 1 of the periodic table; they have 1 valence electron. They are highly reactive and form very strongly basic hydroxides.

Base: A substance with a high pH (more than 7). The higher the pH, the more basic (due to more OH- ions). Also known as alkalies, they can neutralise acids and form salts.

Diatomic molecules: Molecules that are comprised of two atoms.

Group: The columns of the periodic table. Elements of the same group have the same number of valence electrons.

Halogens: Elements in the 7th group of the periodic table. They have seven valence electrons, and are all non-metals, whose hydroxides are strongly acidic.

Inert: A substance that does not react. Noble gases are unreactive, therefore they are inert.

Metal: Elements that conduct electricity and heat, and whose hydroxides are basic. They bond together in a giant metallic crystal, with a sea of free electrons.

Noble gas: An element in the last group of the periodic table, group 0 or group 8. It is inert, and has a full outer shell of electrons

Non-metal: Elements that generally do not conduct electricity (carbon is an exception). Form covalent bonds involving a shared pair of electrons, and their hydroxides are acidic.

Period: The rows of the periodic table. Indicates how many shells of electrons there are.

Periodic table: A table of organisation for the chemical elements, developed by Mendeleev  (though not quite as we know it today, and there are many other versions)

Valence electrons: Outer-shell electrons

Section 1 i) Key Words

Anode: Positive electrode. Attracts negative anions.

Anions: Negatively charged ions

Cathode: Negative electrode. Attracts positive cations.

Cations: Positively charged ions

Electrode: A conductor placed in an electrolyte to electrolyse it

Electrolysis: The process by which a molten or aqueous ionic compound is separated by passing a current through.

Electrolyte: A molten or aqueous ionic compound that conducts electricity.

Half equation: An ionic half equation includes only half a chemical reaction, it just shows what is happening at the individual electrodes with the transfer of electrons.

Section 1 h) Key Words

Delocalised electrons: Electrons that are not tied to a specific nucleus, they are free to move around and allow electricity to be conducted.

Ductile: Able to be stretched out/pulled out into a wire. Metals are ductile.

Giant structure: A constantly repeating lattice structure of molecules, it doesn't end until there aren't enough molecules to add more.

Malleable: Easily bent when force is applied, the opposite of brittle.

Section 1 g) Key Words

Allotrope: The different molecular forms in which an atom can exist.

Covalent bond: A bond involving the attraction of a pair of electrons and a pair of nuclei from two non-metal atoms

Diamond: An allotrope of carbon with a tetrahedral structure. Used in jewellery and in power tools, as it is the hardest material naturally occurring on Earth and can cut through virtually any solid.

Intermolecular forces: The weak forces of attraction between covalent molecules

Graphite: An allotrope of carbon in a layered structure that easily slides. Used in pencils and as a lubricant, as it transfers easily and slides easily.

Tetrahedral: An atom directly bonded with four other atoms: it has four covalent bonds. Structure of diamond.

Section 1 f) Key Words

Anion: Negatively charged ion

Cation: Positively charged ion

Ion: Charged particle, atom with extra electron/s or missing electron/s

Oxidation: Loss of electrons

Reduction: Gain of electrons

Section 1 e) Key Words

Balanced equation: A chemical equation that is written so the numbers of molecules do not change from one side to the other of the equation.

Concentration: How many molecules of a substance there are in a fixed volume, how dilute it is.

Crucible: A piece of apparatus - a ceramic "pot" that can be used for heating substances to high temperatures. Includes a lid.

Percentage Yield: The percentage of a substance you collect as a percentage of how much was created in a reaction.

State Symbol: Indicates the state of a chemical at room temperature in a reaction (unless otherwise specified), e.g. (g) for gas, (aq) for aqueous. Found in a chemical equation written in the bottom right corner of a molecule.

Yield: The amount of a substance you retrieve from an experiment/chemical reaction

Section 1 d) Key Words

Ar/Relative Atomic Mass: The mass of a single atom relative to Carbon 12

Avagadro's Number: The number of particles of a substance in 1 mole of it: 6.022 x 10^23

Molar Volume: The volume of space 1 mole of any gas takes up at room temperature and pressure: 24dm^3 or 24000cm^3

Mole: The number of particles it takes for Mr to equal mass in grams. Avagadro's number of particles are in 1 mole.

Mr/Relative Formula Mass: The mass of a molecule relative to carbon 12.

Section 1 c) Key Words

Atom: The smallest chemical particle. Made up of positively charged central nucleus (protons and neutrons) and shells of negatively charged electrons.

Atomic Number: The number of protons in an atom

Electron: Negatively charged subatomic particle with a relative mass of 0. Orbits the nucleus in shells and can be transferred to other atoms to form charged ions.

Group: The vertical organisation of elements in the periodic table. From left to right, there are 8 groups: 1, 2, 3, 4, 5, 6, 7, 0

Ion: A charged chemical particle, an atom that has lost or gained electrons.

Isotope: Atoms with the same number of protons but different numbers of neutrons

Mass Number: Number of protons + Number of neutrons

Nucleus: The central part of an atom comprised of protons and neutrons. Positively charged.

Neutron: A subatomic particle without charge and relative mass 1. Found in the nucleus.

Period: The horizontal organisation in the periodic table, numbers increasing top to bottom.

Periodic Table: A way of organising the chemical elements by atomic number, with patterns relating to reactivity and other properties.

Proton: A positively charged subatomic particle with a relative mass of 1. Found in the nucleus.

Relative Atomic Mass: The mass of an atom, relative to carbon 12.

Valence Electron(s): The electrons found in the outer electron shell.  

Section 1 b) Key Words

Atom: The smallest particle of a chemical element that can exist.

Chromatography: The separation of different particles of a solution e.g. pigments in ink, by placing them on paper and allowing a solvent to transport the particles up the paper to different distances through capillary action.

Compound: Two or more chemically bonded elements. They can be ionic or covalent.

Crystallisation: The formation of crystals through evaporation

Diffusion: The net movement of particles from an area of high concentration to an area of low concentration.

Dilution: Making a substance weaker (e.g. HCl can be diluted so it is less corrosive, food dye disperses through a liquid and becomes weaker) through the addition of other substances.

Element: A substance found on the periodic table that cannot chemically be split up into simpler substances. Its atoms have equal numbers of electrons and protons, resulting in balanced charge.

Evaporation: The state change of liquid to vapor, used to separate a solid from a liquid solution.

Filtration: Separation using a funnel and filter paper to remove large, insoluble particles.

Fractional distillation: Heating a mixture of liquids into a fractionating column to separate them into fractions which differ in boiling point. The gases then pass through a a tube where they are condensed and collected as a liquid again.

Magnetic separation: Separation of magnetic and non-magnetic substances, used industrially in recycling plants, etc.

Mixture: Two or more compounds or elements that are physically mixed but not chemically bonded, e.g. air or steel.

Molecule: A group of atoms bonded together in the simplest form of a chemical compound that can take part in a chemical reaction.

Separation: Techniques of removing different parts of a mixture from each other to obtain substances combined within it.

Sieving: Removing larger insoluble particles from smaller insoluble particles by passing it through a sieve. Different sized holes in sieves can be used for different purposes

Simple distillation: Separating a mixture of liquids through heating, then condensing the vapor and collecting the purer substance Works best with mixtures containing few different chemicals (e.g. separating ethanol and water)

Section 1 a) Key Words

Boiling: The change of state from liquid to gas with an increase in thermal energy, to the substance's boiling point. The liquid becomes a gas because the particles are able to spread apart enough to change from a liquid phase to a gaseous phase.

Boiling Point: The temperature at which boiling occurs in a certain liquid, e.g. water's boiling point is 100ºC at the pressure of 1 atm., as boiling point increases as pressure increases due to the pressure exerted on the particles changing their ability to spread and boil.

Condensing: The change of state from gas to liquid. This happens when a gas cools, often upon colliding with a solid surface, so the particles collect and become more dense until they change physical state.

Freezing: A change of state from liquid to solid. When the particles lose kinetic energy they move less and become more densely packed. Attractions between the particles cause bonds or intermolecular forces form between the particles to keep them in fixed positions.

Gas: A state of matter in which the particles move randomly in different directions, colliding with other particles and surfaces and changing direction. The particles are spread over a wide space; it is the least dense state of matter. It has no fixed shape or volume, meaning it can be compressed and squeezed, and it flows.

Liquid: A state of matter involving randomly organised particles that are fairly closely packed, but less densely than in a solid. It has a fixed volume but no fixed shape; it will take the shape of its container. The particles are able to move and flow over each other.

Melting: The change of state from solid to liquid. Due to an increase in thermal energy, the kinetic energy of the particles increases, making the bonds or intermolecular forces break and allowing the particles to be freed from their fixed positions and flow over one another.

Solid: A state of matter in which the particles are closely and regularly packed and vibrate about a fixed point. It does not flow and has a fixed shape and volume, and it is the most dense state of matter.

Sublimation: The change of state from solid to gas, skipping the liquid phase. (Deposition is the same but changing state the opposite direction, from gas to solid). Examples include carbon dioxide, which sublimes into dry ice, or when the sun heats a field of snow. Sublimation occurs when the total pressure of the atmosphere is less than the vapor pressure of the compound, and the temperature has not yet reached the substance's melting point. The particles spread out quickly to change state from solid to gas quickly.