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How would you organize these?

Early Periodic TablesJ.W. DobereinerGroup elements in triads (sets of 3)Based on chemical/physical propertiesDidnt work well with metalsJohn NewlandsLaw of OctavesProperties of elements seem to change every 8th elements

Modern Periodic TableDmitri MendeleevGroups elements by atomic mass Groups = vertical columns Periods = horizontal linesPredicted details for elements not yet discoveredPeriodicityRepeating patterns at set intervalsPeriodic Lawpattern in chemical and physical properties of the elements when they are arranged by increasing atomic numbers

Modern Periodic TableHenry MoseleyDesigned periodic table used todayOrdered elements by increasing atomic numbers

Reading the Periodic TableElementAtomic symbolAtomic numberAtomic mass

PeriodsPeriod shows the number of shells possible for those elements2n2 = max # of electrons Period #/ Shell #Number of electrons in sublevels Max # of electronsIn Shelln=122n=288n=31818n=43232n=53250n=61872n=7898

GroupsA Group- representative elementsGroup # = Valence electron #Special Names:I A = Alkali MetalsII A= Alkaline Earth MetalsVII A= HalogensVIII A= Nobel Gases

Element Ion ChargesElements are most stable when they have a full set (8) of valence electronsAs Group # = Ion chargeGroup I A = +1; H+, K+, etc..Group IIIA = +3; B+3, Al+3, etc..Group VIIA =Group VIA= -2; O-2, Se-2, etc Group IVA=

-1; F-, Cl-, etc+4/-4