Ns2 np3 valence shell10/26/2022 Bases on the electronic configuration, we can classify elements in to four types. According to the newIUPAC recommendations the groups are numbered form 1 to 18. These also include a part of inner transition elements, The atom of the element in a single verticalcolumn have the same or very similar electronic configurationsinthehighestoccupiedorbitalsandarethereforesaidtobelongtothesame GROUP or FAMILYof elements. All these elementsare naturally occurring but rest are radioactive with very short half lives. VII PeriodLike the sixth period would have a theoreticalmaximumof 32 elements.This period howeverisincompleteandatpresentcontains19elementsstartingfrom 87Fr (francium) to 92U. This period includes the 4f shell that includes Lanthanides (58Ce.71Lu). V PeriodStarts with rubidium and contains 18 elements : 37Rb,38Sr, 39Y, 40Zr, 41Nb, 42Mo, 43Tc, 44Ru, 45Rh, 46PD, 47Ag, 48CD 49In, 50Sn, 51Sb, 52Te, 53I, 54Xe.The fifthVI PeriodConsists of 32 elements, starting from cesium (55Sc) and ending with radon. #Ns2 np3 valence shell pdf#id4575890 pdfMachine by Broadgun Software- a great PDF writer!- a great PDF creator! - INORGANICCHEMISTRY By- P.K.SINHA Contact at IV Periodstartswithpotassiumandcontains18elements: 19K, 20Ca, 21Sc, 22Ti, 23V, 24Cr, 25Mn, 26Fe, 27Co, 28Ni, 29Cu, 30Zn, 31Ga, 32Ge, 33As, 34Se, 35Brand 36Kr and is known as long period. IIIrd PeriodContains8elements: 11Na, 12Mg, 13Al, 14Si,15S, 16S, 17Cl,and 18Ar.TheIIIrd period is also known as short period. IInd PeriodContains8elementsnamely 3Li, 4Be, 5B, 6C, 7N, 8O, 9Fand 10Neisknownasthe short period. PERIODS 1ST PeriodContain only 2 elements namely 1H, 2He and is the shortest period. Altogether there are seven periods and 18 groups. Elements having similar chemical and physical properties appear in vertical columns and are known as GROUPS or FAMILIES. The long form of the periodic table is the most convenient and the most widely used and is presented here. LONG FORM OF THE PERIODIC TABLE There are many forms of the periodic tale. 2.Due to this systematic work and far reaching ideas, Mendelleve is usually given the creditforthedesignoftheperiodictableasweknowittoday.Themodernperiodic tableisessentiallysimilartothatofMendellevswithaseparatecolumnaddedfor noble gases which were not discovered until then THE MODERN PERIODIC TABLE The modern version of the periodic law is stated as: Thephysicalandchemicalpropertiesoftheelementsaretheperiodicfunctionsof their atomic masses. Note:1IntruesenseofwordsMendelleveorganizedtheelementsaccordingtoaregular increase or decrease in valence (the capacity of an element to combine with another element). He named these elements as eka-sillicon, eka aluminumand eka-boron because he believed that they would be similar to silicon, aluminum and boron respectively. He had thecourageandforesighttoleavegapsinthetableforelementswhichwerenotknownat thattime.Hecouldpredictthepropertiesofthosemissingelementsfromastudyofthe propertiesofotherelementsinthesamegroup.Forexample,germanium,galliumand scandium sere not discovered at that time when Mendeleev proposed his periodic table. His proposal was even backed by the predictions for the undiscovered elements. He therefore, ignored the order of atomic weights to group together elements which had similar chemical properties. The properties of the elements, as well as the formulae and properties of their compoundsdependinaperiodicmannerontheatomicweightofthe elements Therewereafewpositionsinthetable(e.g.Ar,K,andTe,I)whereelements havingthehigherweightprecededtheelementwithlowermassforproper periodicity in the properties. In particular, Mendelleve relied on the similarities in the chemical formulae of the compounds formed by the elements. He used a broader range of physical and chemical properties to classify the elements. Lother Meyer used the physical properties such as the atomic volume, melting point and boiling point to arrive at his table of elements. NEWLANDS LAW OF OCTAVES:- JohnA.R.Newlandsin1865-66developedhislawofoctaves.Hefoundthatwhenthe elements were arranged in order of their increasing atomic weights, any given elements was similartotheeitherelementthatfollowedit.Forexample,K,thesixteenthelementin Newland's list and properties similar to Li, the second element in the list.MENDELEVES PERIODIC TABLE In these tables, the elements were arranged in the order of their increasing atomic weights. However, only a limited number of such triads could be found. For example, (Li, Na, K) and (Cl, Br, I). The properties of the middle element in a triad is the average of the properties of the first and the third elements. INORGANICCHEMISTRY By- P.K.SINHA Contact at THE PERIODIC TABLE DOBEREINERS TRIADS:- Dobereiner classified elements into groups of three, called triads.
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