Help
Options
Term
Compound
click to flip
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't know
Term
Covalent Bond
Remaining cards (55)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
AQA C2 Key Words
Key Words for AQA GCSE Chemistry Topic C2
| Term | Definition |
|---|---|
| Compound | A substance made when two or more elements are chemically bonded together. |
| Covalent Bond | The attraction between two atoms that share one, or more pairs of electrons. |
| Covalent Bonding | The attraction between two atoms that share one, or more pairs of electrons. |
| Delocalised Electron | bonding electron that is no longer associated with any one particular atom. |
| Dot and Cross Diagram | a drawing to show the arrangement of the outermost electrons only of the atoms or ions in substance. |
| Double Bond | a covalent bond formed by the sharing of two pairs of electrons. |
| Giant Covalent Structure | a huge 3D network of covalently bonded atoms. (e.g. the giant lattice of carbon atoms in diamond or graphite. |
| Giant Lattice | a huge 3D network of atoms or ions (e.g. the giant ionic lattice in sodium chloride). |
| Ion | a charged particle produced by the loss or gain of electrons. |
| Ionic Bond | the electrostatic force of attraction between positively and negatively charged ions. |
| Ionic Bonding | the electrostatic force of attraction between positively and negatively charged ions. |
| Mixture | when some elements or compounds are mixed together and intermingle but do not react together ( i.e. no new substances are made). A mixture is NOT a pure substance. |
| Macromolecule | A Giant covalent structure. e.g. diamond- the diamond in a ring is one massive moleucule |
| Monomers | Small reactive molecules that react together in repeating sequences to form a very large molecule (a polymer). |
| Nanoscience | The study of very tiny particles or structures between 1 and 100 nanometres in size- where 1 nanometre = 1x10-9metres |
| Polymer | A substance made from very large molecules made of many repeating units e.g. poly(ethene). |
| Polymerisation | The reaction of monomers to make a polymer. |
| Atomic Number | The number of protons (which equals the number of electrons) in an atom. It is sometimes called the proton number. |
| Empirical Formula | The simplest ratio of elements in a compound. |
| Isotope | Atom that has the same number of protons but a different number of neutrons. i.e. the same atomic number but a different mass number. |
| Mass Number | The number of protons plus the number of neutrons in the nucleus of an atom. |
| Mole | The amount of substance in the relative atomic or formula mass of a substance in grams. |
| Molecular Formula | The chemical formula that shows the actual numbers of atoms in a particular molecule (e.g. C2H4). |
| Percentage Yield | The actual mass of product collected in a reaction divided by the maximum mass that could have been formed in theory, multiplied by 100. (i.e. (actual yield/theoretical yield) x 100) |
| Relative Atomic Mass,Ar | The average mass of the atoms of an element compared to carbon-12 (which is given the mass of exactly 12). The average mass must take into account the proportions of the naturally occurring isotopes of the element. |
| Relative Formula Mass, Mr | The total of the relative atomic masses, added up in the ratio shown in the chemical formula, of a substance. |
| Reversible Reaction | A reaction in which the products can re-form the reactants. |
| Symbol Equation | A balanced chemical equation showing the formula for each reactant and product in the reaction e.g. H2 + Cl2 = 2HCl |
| Word Equation | A way of describing what happened in a chemical reaction by showing the names of all the reactants and products they form. |
| Chromatography | The process by which small amounts of dissolved substances are separated by running a solvent along a material such as absorbent paper. |
| Gas Chromatography | The process of separating the components in a mixture by passing the vapours through a column and detecting them as they leave the column at different times. |
| Equilibrium | The point in a reversible reaction in which the forward and backward rates of reaction are the same. Therefore, the amount of substances present in the reacting mixture remain constant. |
| Mass Spectrometer | A machine that can be used to analyse small amounts of a substance to identify it and to find its relative molecular mass. |
| Molecular Ion Peak | The peak on the mass spectrum of a substance which tells us the relative molecular mass of the substance. The peak is produced by the heaviest positive ion shown on the mass spectrum. |
| Catalyst | A substance that speeds up a chemical reaction but remains chemically unchanged itself at the end of the reaction. |
| Collision Theory | An explanation of chemical reactions in terms of reacting particles colliding with sufficient energy for a reaction to take place. |
| Endothermic | A reaction that takes in energy from the surroundings. |
| Exothermic | A reaction that gives out energy to the surroundings. |
| Activation Energy | The minimum energy needed to start off a reaction. |
| Acid | A sour substance which can attack metal, clothing or skin. The chemical opposite of an alkali. When dissolved in water, its solution has a pH number of less than 7. Acids are proton (H+ ion) donors. |
| Alkali | Its solution has a pH of more than 7. |
| Aluminium | A low density, corrosion resistant, metal used in many alloys including those used in the aircraft industry. |
| Aqueous Solution | The mixture made by adding a soluble substance to water. |
| Base | The oxide, hydroxide or carbonate of a metal that will react with an acid, forming a salt as one of the products. (If the base dissolves in water it is called and alkali). Bases are proton (H+ ion) acceptors. |
| Brine | A solution of sodium chloride in water. |
| Electrolysis | The breakdown of a substance containing ions by electricity. |
| Electrolyte | A liquid, containing free-moving ions, that is broken down by electricity in the process of electrolysis. |
| Half Equation | An equation that describes reduction (gain of electrons) or oxidation (loss of electrons), such as the reactions that take place at the electrodes during electrolysis. |
| Neutral | A solution with a pH value of 7 which is neither acidic nor alkaline. Alternatively, something that carries no overall electronic charge- neither positively or negatively charged. |
| Neutralisation | The chemical reaction of an acid with a base in which they cancel each other out, forming a salt and water. If the base is a carbonate or hydrogencarbonate, carbon dioxide is also produced in the reaction. |
| Oxidation | The reaction when oxygen is added to a substance (or when electrons are lost). |
| Oxidised | A reaction when oxygen is added to a substance (or when electrons are lost). |
| pH Scale | A number which shows how strongly acidic or alkaline a solution is. Acids have a pH value of less than 7 (pH 1 is strongly acidic). Alkalis have a pH value above 7 (pH 14 is strongly alkaline). A neutral liquid has a pH value of 7. |
| Reduction | A reaction in which oxygen is removed (or electrons are gained). |
| Salt | A compound formed when some or all of the hydrogen in an acid is replaced by a metal ( or by an ammonium ion). For example, potassium nitrate KNO3 (from nitric acid) |
| Universal Indicator | A mixture of indicators which can change through a range of colours depending on the pH of the solution. Its colour is matched to a pH number using a pH scale. It shows how strongly acidic or alkaline liquids and solutions are. |
Created by:
willocka
Popular Chemistry sets