IB›IB Chemistry HL›Mind mapsS3.1 The periodic table: Classification of elementsIB Chemistry HL: Mind mapStudy pack PDFAlso for this subtopic:Revision notesFlashcardsSubtopic testCover factsTable and trendsPeriods = outer level; groups = valence electronsAcross a period radius decreasesIE, electron affinity, electronegativity increaseDown a group the trends reverseCations smaller, anions larger than atomsOxidesNa₂O, MgO basic; Al₂O₃ amphotericSiO₂, P₄O₁₀, SO₃ acidicNaX2O+HX2O→2 NaOH\ce{Na2O + H2O -> 2NaOH}NaX2O+HX2O2NaOHSOX3+HX2O→HX2SOX4\ce{SO3 + H2O -> H2SO4}SOX3+HX2OHX2SOX4[CoClX4]X2−\ce{[CoCl4]^2-}[CoClX4]X2−: cobalt is +2IE dipsBe → B, Mg → Al: p higher than sN → O, P → S: paired p electron repelledTwo dips are evidence for sublevelsPattern 2, 3, 3 gives one s, three pPeriodic tabletrends and transition metalsspdfTransition elementsIncomplete d-sublevel in atom or ionZinc is not a transition elementVariable oxidation states, e.g. Mn +2, +4, +7High melting points, paramagneticCatalysts: Fe in Haber processForm complex ions with ligandsIons and colour4s electrons removed before 3dFeX3+\ce{Fe^3+}FeX3+ = [Ar]3d5[\text{Ar}]3d^5[Ar]3d5; CuX2+\ce{Cu^2+}CuX2+ = [Ar]3d9[\text{Ar}]3d^9[Ar]3d9Ligands split the d-sublevelElectron promotion absorbs visible lightObserved colour is the complementary colour3d⁰ or 3d¹⁰ ions are colourlessExam tipsDo not say N is stable as 'half full'Explain O's paired electron repulsion insteadWrite the atom first, then remove 4sOrange absorbed looks blue