Periodic G Ludhiana

Submitted by Mrs. Anju Soni Lecturer Chemistry

Under the Guidance oF Mr. Jaswinder Singh Teacher Trainer

Index S.No

Contents

1

Acknowledgement

2

Subject Matter

3

References

Acknowledgement This Project has been completed under the able guidance of Mr. Jaswinder Singh ( Computer Faculty ) who has provided me with all the necessary support for completing this project. I am thankful to Mrs. Barjinder Kaur Principal of J.L.N.G.G.S.S.S Jawahar Nagar Ludhiana and DE trainees for their corporation. Thanks to Digital Equalizer Program for providing an opportunity to learn and to enable me to make such project which me help me a lot in my

EARLIER ATTEMPTS TO CLASSIFY ELEMENTS

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Mendeleyev, Dmitry Ivanovich (1834-1907), Russian chemist, best known for his development of the periodic law of the properties of the chemical elements. He classified the elements according to their chemical properties. In 1869 he published his first version of what became known as the periodic table, in which he demonstrated the periodic law. In 1871 he published an improved version of the periodic table,

Mendeleev Periodic Law ELEMENTS SHOW A PERIODICITY (REGULAR APATTERN ) OF PROPERTIES WHEN THEY ARE ARRANGED ACCORDING TO ATOMIC WEIGHT.

General plan of Mendeleev;s Periodic table  

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It consists of six horizontal rows called periods &nine vertical columns known as groups. Nine groups are numbered from 1 to 8 & zero (the number of zero group were not discovered at that time) Each group from 1 to 7 is further sub divided into sub-groups A & B. Group 8 consists of three vertical columns each one containing three elements. Six horizontal rows called periods are numbered from 1 to 6.

SIGNIFICANCE of MENDELEEV;S PERIODIC TABLE  

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Proved very of Mendeleev;s table useful in simplifying the study of elements & their compounds. At the time when Mendeleev ;s periodic table was formulated only 56 elements were known. Therefore while arranging the elements according to their properties, Mendeleev left some blank spaces or gaps. These gaps represented unknown elements. Further he predicted the properties of these unknown elements on the basis of their positions His chart and theories gained increased acceptance when three predicted elements—gallium, germanium, and scandium—were subsequently discovered. This table has helped in correcting the doubtful atomic weights of some elements

Defects in Mendeleev;s periodic table  

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Anomalous position of hydrogen Position of isotopes, not given in table Metals and non metals not separated Similar elements separated in table Dissimilar elements placed together in the same group Lanthanides and actinides not provided separate and proper place

MODERN PERIODIC TABLE • In the modern table, elements with similar properties fall into columns called groups or families. • Group 1 of the periodic table, for example, contains a number of soft metals, all of which react vigorously with water to form hydrogen gas

Structural Features Of The Present Form Of Periodic Table 

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Consists of eighteen vertical columns & seven horizontal rows . The vertical columns are known as GROUPS or FAMILIES. The horizontal rows are called PERIODS.

Ar r angement of eleme nts i n moder n perio dic t able

 The elements within the modern periodic table are arranged from left to right, top to bottom, in order of increasing atomic number. An element’s atomic number is the number of protons in its nucleus. There are 92 naturally occurring elements, ranging from hydrogen, which has atomic number 1 to uranium whose atomic number is 92.

MODERN PERIODIC LAW •

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Periodic Law, in chemistry, law stating that many of the physical and chemical properties of the elements tend to recur in a systematic manner with increasing atomic number. Progressing from the lightest to the heaviest atoms, certain properties of the elements approximate those of precursors at regular intervals of 2, 8, 18, and 32. For example, the 2nd element (helium) is similar in its chemical behavior to the 10th (neon), as well as to the 18th (argon), the 36th (krypton), the 54th (xenon), and the 86th (radon). The chemical family called the halogens, composed of elements 9 (fluorine), 17 (chlorine), 35 (bromine), 53 (iodine), and 85 (astatine), is an extremely reactive family.

2He 9F

10Ne

17Cl

18Ar

35Br

36Kr

53I

54Xe

85At

86Rn

Notations for the IUPAC Nomenclature of elements

Digits

0 1 2

Name nil un bi

Abbreviation n u b

3

tri

t

4

quad

q

5

pent

p

6

hex

h

7

sept

s

8 9

oct enn

o e

Notations for the IUPAC Nomenclature of elements Atomic no (Z)

IUPAC Name

symbol

110

Un+un+nil+ium=Ununnilium

Uun

111

Un+un+un+ium=Unununium

Uuu

112

Un+un+be+ium=Ununbium

Uub

113

Un+un+tri+ium=Ununtrium

Uut

114

Un+un+quad+ium=Ununquadium

Uuq

115

Un+un+pent+ium=Ununpentium

Uup

116

Un+un+hex+ium=Ununhexium

Uuh

117

Un+un+sept+ium=Ununseptium

Uus

118

Un+un+oct+ium=Ununoctium

Uuo

119

Un+un+enn+ium=Ununennium

Uue

GROUPS  

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There are 18 groups in the periodic table. Each group consists of a number of elements having same electronic configuration of the outermost (valence) shell. These groups are numbered from 1 to 18. The elements in a a group are separated by definite gap of (2,8,8,18,18,32)

MODERN PERIODIC TABLE 1 H

2 He

3 Li

4 Be

5 B

6 C

7 N

8 O

9 F

10 Ne

11 Na

12 Ms

13 Al

14 Si

15 P

16 S

17 Cl

18 Ar

19 K

20 Ca

21 Sc

22 Ti

23 V

24 Cr

25 Mn

26 Fe

27 Co

28 Ni

29 Cu

30 Zn

31 Ga

32 Ge

33 As

34 Se

35 Br

36 Kr

37 Rb

38 Sr

39 Y

40 Zr

41 Nb

42 Mo

43 Tc

44 Ru

45 Rn

46 Pd

47 Ag

48 Cd

49 In

50 Sn

51 Sb

52 Te

53 I

54 Xe

57 Cs

56 Ba

71 Lu

72 Hf

73 Ta

74 W

75 Re

76 Os

77 Ir

78 Pt

79 Au

80 Hg

81 Tl

82 Pb

83 Bi

84 Po

85 At

86 Rn

87 Fr

88 Ra

103 Ra

104 Rf

105 Db

106 Sg

107 Bh

108 Hs

109 Mt

110 Ds

111 Uuu

112 Uub

113 Uut

114 Uuq

115 Uup

116 Uuh

57 La

58 Le

59 Pr

60 Nd

61 Pm

62 Sm

63 Eu

64 Gd

65 Tb

66 Dy

67 Ho

68 Er

69 Tm

70 Yb

89 Ac

90 Th

91 Pa

92 U

93 Np

94 Pu

95 Am

96 Cm

97 Bk

98 Cf

99 Es

100 Fm

101 Md

102 No

Nonmetals Other Metals Noble Gases

Alkaline Earth Metals Actinide Series Alkali Metals

Transition Metals Lanthanide Series Halogens

Normal or Representative Elements (s & p-block) The elements of first two groups ,i.e., 1& 2 on the extreme left involve the filling of s-orbitals while those of the last six groups,i.e.,13 to18 on extreme left involve the filling of electrons in the p-orbitals of the valence shell. The elements of these eight groups 1,2,13,14,15,16,17 &18are collectively called Normal or Transition Elements .

1H 3Li

4Be

11Na

12Ms

19K

20Ca

37Rb

38Sr

57Cs

56Ba

87Fr

88Ra

s-Block elements Elements in which the last electron enters the s-orbital of their respective outermost shells are called s-Block elements. The block is situated on the left hand side of the periodic table. Since s-subshell has only one orbital which can accommodate only two electrons,therefore,there are only two groups of s-block elements. It contains 13 elements in two groups (group1&2). The elements of group 1 are Hydrogen & Alkali metals, group 2 are Helium & Alkaline earth metals with general electronic configuration ns1 & ns2 respectively where n stands for outermost shell.

Important Characteristics of s-Block Elements    

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With exception of Hydrogen,s-block elements are are soft metals have low melting & boiling points have low ionization enthalpies are highly reactive & readily form univalent (+1) or bivalent(+2) positive ions by losing the valence electrons impart characteristic colour to the flame are good conductors of heat & electricity are strong reducing agent their hydroxides are strong bases

P-Blo ck El eme nts  Elements in which the last electron enters any one of the three p-orbitals of their respective outermost shells are called p-block elements.  This block is situated on the right hand side of periodic table.  It contains 31 elements in six groups (13,14,15,16,17,18 excluding Helium)  Their general electronic configuration is ns2 np1-6 where n stands for outermost shell.

Important Characteristics of p-Block Elements 

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Includes both metals & non-metals. the metallic character increases from top to bottom within a group & non-metallic character increases from left to right along a period in this block. Ionization energies are relatively higher than s-block elements. Mostly form covalent compounds. Generally bad conductors of heat & electricity(except metals). Most of the elements show variable oxidation states. Their oxidizing character increases from left to right & reducing character increases from top to bottom.

TRANSITION or d-Block Elements 

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Elements in which last electron enters any one of the five d-orbitals of their respective penultimate shells are called d-block elements. This block is situated in between s & p blocks. The d-block elements are known as the TRANSITION ELEMENTS because the properties of these elements are midway between those of s & p-block elements. There are 36 elements in four transition series( or periods) in this block. First three transition series contain ten elements each while fourth is incomplete. General electronic configuration of d-elements are (n-1)d1-10 ns1-2

Important Characteristics of d-Block Elements hard, malleable, ductile metals with high melting & boiling point. good conductors of heat & electricity. Show variable oxidation states. ionization enthalpies are between s & p-block elements. form both ionic & covalent compounds. Compounds are generally coloured & paramagnetic. form coloured complexes Most of transition elements such as Mn, Co, Ni, Cr, V and their compounds are used as catalysts..

INNER TRANSITION or f-Block Elements 

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Elements in the last electron enters any one of the seven f-orbitals of their respective ante-penultimate shells are called f-block elements. These are called inner transition elements because these form transition series within the transition elements of d-block. There are 28 elements in two series of f-block each containing 14 elements. Elements in first row are called LANTHANOIDS or 4f-elements. Elements of second row are called ACTINOIDS or 5f-elements This block is situated below s, p & d-blocks. General electronic configuration of f-block elements are (n-2)f1-14(n-1)d0-1ns2

Important Characteristics of f-Block Elements • heavy metals with high melting & boiling points. • show variable valency. • form coloured compounds. • most of the elements of the actinide series are radioactive. • have high tendency to form complexes

PER IO DS  The horizontal rows from left to right in the periodic table are called Periods.  Long form of periodic table contains seven periods numbered as 1,2,3,4,5 , 6 & 7.  Each period consists of a series of elements whose atoms have the same principal quantum number (n) of the outermost shell.

Number of Elements in each Period PERIOD No. of Orbital being No of electrons or Energ filled elements in each y level Period being filled 1

n=1

1s

2

2

n=2

2s,2p

2+6=8

3

n=3

3s,3p

2+6=8

4

n=4

4s,3d,4p

2+10+6=18

5

n=5

5s,4d,5p

2+10+6=18

6

n=6

6s,4f,5d,6p

2+14+10+6=32

7

n=7

7s,5f,6d,7p

2+14+10+6=32

VARIATION OF SIZE OF ATOMS IN PERIODIC TABLE 

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The size of the atoms of an element varies in a regular way across the periodic table, increasing down the groups (columns), and decreasing along the periods (rows) from left to right. The size of an atom is largely determined by its electrons. The electrons are arranged in shells surrounding the nucleus of each atom. The top elements of every group have only one or two electron shells. Atoms of elements further down the table have more shells and are therefore larger in size. Moving across a period from left to right, the outermost electron shell fills up but no new shells are added. At the same time, the number of protons in the nucleus of each atom increases. Protons attract electrons. The greater the number of protons present, the stronger the attraction that holds the electrons closer to the nucleus, and the smaller the size of the shells.

VARIATION OF ATOMIC RADIUS ALONG PERIOD & GROUP Atomic radius decreas es along a period and increas es along a group

ADVANTAGES OF LONG FORM OF PERIODIC TABLE Relate the position of an element in the table to its electronic configuration more readily. Easy & simple to remember & reproduce. Elements in the same group( s,p, d, f ) show marked similarities due to similar outer electronic configurations. Thus there is logical classification of groups in it. Based upon the atomic number which is more fundamental property of elements. Hence there is no problem of placing the isotopes of an element separately. Properties of new elements can be predicted even before their discoveries. Lanthanoids & actanoids, which have properties different from other groups are placed separately at the bottom of periodic table.

DEFECTS OF LONG FORM OF PERIODIC TABLE Position of Hydrogen does resemble fully with alkali metals but has been placed along with them. It also resemble halogens as well as carbon. Lanthanoids & actanoids have not been accommodated in the main body of this periodic table. According to electronic configuration , Helium should be placed in s-block whereas it is placed in p-block.

REFERENCES ► NCERT

Chemistry for Senior Secondary Classes ► Modern’s abc Chemistry for 10+1 Classes ► Systematic Chemistry for 10+1 Classes ► Pardeep’s Chemistry for 10+1 Classes ► Microsoft Encarta Encyclopedia Deluxe 2005