1. School of ElementsSection IChapter 1Std XMarks without option 3Marks with Option 4Science & TechnologyPresented ByAzeem khan

2. Objective:- 1.1 Dobereiner's Traids 1.2 Newland's Law of Octaves 1.3 Mendeleev's Periodic Table 1.3.1 Main Feature's of Mendeleev's Periodic Table 1.3.2 Merit's of Mendeleev's Periodic Table 1.3.3 Demerit's of Menvdeleev's Periodic Table 1.4 Modern Periodic Table 1.4.1 Position of Elements on Modern Periodic Table 1.4.2 Merit's of Modern Periodic Table over Mendeleev'sPeriodic Table 1.4.3 Periodic Properties 3. 1.1 Dobereiner's Traids In certain triads (groups of three elements)the atomic mass of the central element wasmerely the arithmetic mean of the atomicmasses of the other two elements. 4. Dobereiner's Traids 5. Dobereiner's Traids But in certain triads all the three elementspossessed nearly the same atomic masses,hence the law was rejected. Also, only limited number of triads could bediscovered. 6. 1.2 Newland's Law of Octaves English chemist John AlexanderReina Newlands in 1864 noted that everyeighth element showed similar physical andchemical properties 7. Newland's Law of OctavesNewlands' Law of octaves failed for thefollowing reasons :1. It was not valid for elements that hadatomic masses higher than Ca.2. When more elements were discovered,such as elements from the noble gases such asHe, Ne, Ar, they could not be accommodatedin his table 8. 1.3 Mendeleev's Periodic Table Mendeleev realized that the physical andchemical properties of elements were relatedto their atomic mass in a 'periodic' way, andarranged them so that groups of elementswith similar properties fell into verticalcolumns in his table. 9. Mendeleev's Periodic Table 10. Mendeleev's Periodic Table Sometimes this method of arranging elementsmeant there were gaps in his horizontal rowsor 'periods'. But instead of seeing this as a problem,Mendeleev thought it simply meant that theelements which belonged in the gaps had notyet been discovered. 11. Mendeleev's Periodic Table Modern day periodic tables are expandedbeyond Mendeleev's initial 63 elements. The elements of what we now call a 'period'were listed vertically by Mendeleev. Chemical'groups' are now shown vertically in contrastto their horizontal format in Mendeleev'stable. 12. Mendeleev's Periodic Table In his table arrangement was related to theatomic ratios in which elements formedoxides, binary compounds with oxygenwhereas today's periodic tables are arrangedby increasing atomic numbers 13. Mendeleevs Periodic Table 14. 1.4 Modern Periodic Table Organized on the basis of their properties.Elements are presented in increasing atomicnumber. The main body of the table is a 18 7 grid,with gaps included in to keep elements withsimilar properties together, such as thehalogens and the noble gases. 15. Modern Periodic Table The f-block is not included in the main table, butrather is usually floated below, as an inline f-blockwould make the table impractically wide. The periodic table accurately predicts theproperties of various elements and the relationsbetween properties. provides a useful framework for analyzingchemical behavior, and is widely used inchemistry and other sciences. 16. Reading the Periodic Table: ClassificationNonmetals, Metals, Metalloids, Noble gases 17. Periodic Table: Metallic arrangementLayout of the Periodic Table: Metals vs. nonmetals1IA18VIIIA12IIA13IIIA14IVA15VA16VIA17VIIA233IIIB4IVB5VB6VIB7VIIB8 9VIIIB10 11IB12IIB4567MetalsNonmetals 18. Across the Periodic TablePeriods: Are arranged horizontally across theperiodic table (rows 1-7)These elements have the same number of valence shells.1IA18VIIIA12IIA13IIIA14IVA15VA16VIA17VIIA233IIIB4IVB5VB6VIB7VIIB8 9VIIIB10 11IB12IIB45672nd Period6th Period 19. Down the Periodic TableFamily: Are arranged vertically down the periodic table (columns or group, 1-18 or 1-8 A,B)These elements have the same number electrons in the outer most shells, thevalence shell.1IA18VIIIA12IIA13IIIA14IVA15VA16VIA17VIIA233IIIB4IVB5VB6VIB7VIIB8 9VIIIB10 11IB12IIB4567Alkali Family:1 e- in the valence shellHalogen Family:7 e- in the valence shell 20. Infamous Families of the Periodic TableNotable families of the Periodic Table and some important members:1IA18VIIIA12IIA13IIIA14IVAHalogen15VA16VIA17VIIA233IIIB4IVB5VB6VIB7VIIB8 9VIIIB10 11IB12IIB4567AlkaliAlkaline(earth)Transition MetalsNoble GasChalcogens 21. Periodic Table Organisation 22. Periodic Table: electron behaviorThe periodic table can be classified by the behavior of their electrons1IA18VIIIA12IIA13IIIA14IVA15VA16VIA17VIIA233IIIB4IVB5VB6VIB7VIIB8 9VIIIB10 11IB12IIB4567West (South) Mid-plains East (North)METALSAlkaliAlkalineTransitionMETALLOID NON-METALSNoble gasHalogensCalcogensThese elementstend to give upe- and formCATIONSThese elementswill give up e- oraccept e-These elementstend to accepte- and formANIONS 23. Trend in Atomic RadiusAtomic Radius:The size of at atomic specie as determine by the boundaries of thevalence e-. Largest atomic species are those found in the SW cornersince these atoms have the largest n, but the smallest Zeff. 24. Trend in Ionization PotentialIonization potential:The energy required to remove the valence electron from an atomic specie.Largest toward NE corner of PT since these atoms hold on to their valence e-thetightest. 25. Trend in Electron AffinityElectron Affinity:The energy release when an electron is added to an atom. Most favorable towardNE corner of PT since these atoms have a great affinity for e-. 26. Summary of TrendPeriodic Table and Periodic TrendsIonization Energy: Largest toward NE cornerElectron Affinity: Most favorable NE cornerAtomic Radius: Largest toward SW corner 27. Periodic Table Trends 28. SummaryPeriodic Table: Map of the Building block of matterType: Metal, metalloid and NonmetalGroupings: Representative or main, transition andLanthanide/ActanidesFamily: Elements in the same column have similarchemical property because of similar valence electronsAlkali, Alkaline, chalcogens, halogens, noble gasesPeriod: Elements in the same row have valence electronsin the same shell.