Ocr A Level Chemistry Already Passed

simple molecular lattice {Ans: A three-dimensional structure of molecules, bonded together by weak intermolecular forces.}rate of reaction {Ans: The change in concentration of a reactant or a product in a given time.}limiting reagent {Ans: The substance in a chemical reaction that runs out first.}redox reaction {Ans: A reaction in which both reduction and oxidation take place.}alkali {Ans: A type of base that dissolves in water forming hydroxide ions, OH- (aq) ions.}activation energy {Ans: The minimum amount of kinetic energy that particles need to have in order to react when they collide}troposphere {Ans: The lowest layer of the Earth's atmosphere, extending from the Earth's surface up to about 7 km (above the poles) and to about 20 km (above the tropics).}reflux {Ans: The continual boiling and condensing of a reaction mixture to ensure that the reaction takes place without the contents of the flask boiling dry.}radical {Ans: A species with an unpaired electron.}anhydrous {Ans: A substance that contains no water molecules.}