GCSE›Edexcel GCSE Chemistry›Mind mapsTransition Metals, Alloys & CorrosionEdexcel GCSE Chemistry: Mind mapStudy pack PDFAlso for this subtopic:Revision notesFlashcardsSubtopic testCover factsPropertiesHigh melting pointHigh densityForm coloured compoundsShow catalytic activityIron(II) green, iron(III) orange-brownRustingCorrosion = oxidation of a metalIron needs oxygen and water togetherMissing either → no rustPreventing rustExclude oxygen: paint, oil, greaseExclude water: keep it drySacrificial protection: zinc or magnesiumMore reactive metal loses electrons more easilyTransition metalsalloys and corrosionFeCuNiZnElectroplatingElectrolysis coats a metal with a thin layerObject is the cathodePlating metal ions gain electronsImproves appearance and corrosion resistanceAlloysMixture of a metal with other elementsDifferent-sized atoms distort the layersLayers cannot slide → harder, strongerBrass: copper + zincMagnalium: aluminium + magnesiumAlloy steels: iron + carbonExam tipsRusting needs both oxygen and waterSacrificial: more reactive metal oxidised firstName the property, then link to the use