GCSE›Edexcel GCSE Chemistry›Mind mapsThe Periodic TableEdexcel GCSE Chemistry: Mind mapStudy pack PDFAlso for this subtopic:Revision notesFlashcardsSubtopic testCover factsMendeleevOrdered by properties of elements and compoundsLeft gaps for undiscovered elementsPredictions later proved correctSwapped some elements to keep groups rightModern tableOrdered by increasing atomic numberAtomic number = number of protonsRows are periodsColumns are groupsPeriodic Tablehow it is organisedNaCl2.8.1Metals and non-metalsMetals: left and towards the bottomNon-metals: right and towards the topMetals lose electrons to form positive ionsNon-metals gain or share electronsElectron linkSodium is 2.8.1Period number = number of shellsGroup number = outer-shell electronsSame outer electrons means similar reactionsChlorine 2.8.7: period 3, Group 7Exam tipsCredit Mendeleev for predicting missing elements