This document provides information about the periodic table, including its organization and block structure. It describes the electronic configuration and properties of elements in the s-block, p-block, d-block, and f-block. The s-block contains alkali and alkaline earth metals. The p-block contains nonmetals and metalloids. The d-block contains transition metals. The f-block contains lanthanides and actinides. Each block has characteristic trends in properties corresponding to the orbital being filled.

1. Non metals
Metals
Metalloids
lIA VA VA VIA VIIA VillA
IA HA IVB VB VIB VIIB VIll 8 IB
Groups (UPAC)
10 11 12 13 14 15
15 16 17 18
2 3 4 5 6 9
s-Block elements
(Representative
elements)
.- p-Block elements .
(Representative elements)
2
He
H
Highest
Smallest
iGWsetion
atomk size
goterntia
10
Ne
3 4 d-Block Elements
B
Li Be (Transition Elements)
Maximum
Lightest
solid metal Most
electro
catenation
nEgative
13
Al
14
Si
15
P
16
S
18
Ar
11 12
Na Mg
29
Cu
30
Zn
31
Ga
32
Ge
33
As
34
Se
35
Br
36
28
Ni
27
26
Fe
25
22
Ti
23
21
Sc
19 20
K Ca V Mn Co
Liq. non
metal
50
Sn
51
Sb
47 48 9 53
40 41 42 46
Pd 54
Xe
37 38 39 43 44 45
Rb S Zr Nb Mo TC Ru Rh Ag Cd In
Sublime on
heating
85
At
86
Rn
79
78
Pt
82
Pb
83
Bi
84
Po
57" 75 80
76
Os
77 81
73
Ta
74
W
72
56
Ba
Cs La Hf Re Ir Au Hg T
Highest Heaviest
Heaviest
Less elec-
ronegative
ightest liq.
Lowest
m.pt.,b.pt.
metal gaseous
nonmetal
solidmetal m.pt.
metal
metal
87 88
Ra
89 104 105
111 112 118
106 107
Bh 117
108
Hs
109
Mt
110
Ds
113
Nh
115
Mc
116
Lv
14
Ac Rf Db Sg Rg Cn FI Ts Og
uquid element
of radisactve
hature
1-Block Elements (Inner-Transition Elements)
58 59 60
Nd
61
Pm
62
Sm
63
Eu
70
Yb
71
Lu
69
64
Gd
65
Tb
67
Ho
68
Er
66
Ce Pr
Dy Tm
90
Th 101 102 103
Lr
91 92 93 94 95
Pu Am Cm
96 98
Cf
Long form of periodic table of the elements
97
Bk
99
Es
100
Fm
Pa U Np Md No

2. etronic
Configurations in Periods
el.
Successive period in the periodic table is associated with the filing of the
level (n= 1,n = 2
etc.).Ihe number of elements in each period is twice the number of atomic orbitals
Electronic
cipalenergy level (n
The
p e n i o d
ndicates
thevalue of n for the outermost shell.
a N a i l a b l e
inthe
enero
Period
n e x t
h u g t h e r ,
the energy level that is being filled,
Orbital filling up
Number of elements
1s
First 2 Remark
2s 2p
3s 3p
Shortest period
Short period
Short period
Long period
2 +6 8
S e c o n d
2+6 8
T h i r o
4 4s 3d 4p
2+ 10+6 18
2 +10 +6 18
2+ 14+ 10 +6 32
f o u r t h
5s 4d 5p
Fifth
6 6s 4f 5d 6p Long period
Sixth
7 7s 5f 6d 7p Longest period
2+14+ 10+6 32 Incompleteperiod
S e v e n t h
Fist
period
respondston =1 (K-
nly two elements in the first
period.Ihe valence shell electronic configuration of elements of first period is as follows
-shel). It contains only one orbital i.e., Is orbital. One orbital can accommodate maximum two electrons.
Thusthereare only
H He
1s 1s2
Secondperiod
tcoresponds ton = 2(-she
ght
sht electrons.Thus, there are eight elements in the second period. The valence shell electronic configuration of elements of second
shell). It contains four orbitals i.e., one 2s and three 2p orbitals. Four orbitals can accommodate maximum
periodis as follows
Li Be B C N 0
25 25 252p 252p|2 2p|2s2p 262p 25205
Ne
h al these elements, inner orbital i.e., 1s is completely filled.
Third period
tcoresponds to n = 3 (M- shel). It contains nine orbitals i.e., one 3s, three 3p and five 3d orbitals. According to Aufbau principle,
the energy of 3d-orbitals is higher than that of 4s orbital. So, 4s orbital is filled first and then 3d orbitals. Thus, in third period, only
four orbitals i.e., one 3s and three 3p orbitals are filled. Therefore, again there will be only eight elements in the third period. The
lence shelleectronic configuration of elements of third period is as follows:
Na Mg Al Si P S C Ar
3s 3s 353p353 353p 3s3p 330 353p5
ner orbitals belonging to Kand Lshells are completely filled for these elements.)
Fourth period
tcoresp
Dut
higher than that of 4s orbitals. The filling of the 3d orbitals starts from Sc(Z =21) (3d'4s) and filled up at Zn(Z= 30)(4s3a1)
nds ton=4. It contains 9 orbitals i.e one 4s, three 4p and five 3dorbitals.The 4s orbital has lowerenergythan 3dtherefore,
s t and then flling occurs of 3d and 4p orbitals. So, in fourth period, there are eighteen elements from K[{4s') toKr(4s
As is flled
4p"). Afterfiling of 4s o
orbital, the filling of five 3d orbitals begins since the energy of 3d orbitals is lower than those of 4p orbitals
endsatVi2s constitute the 3d transition series. Thereafter the filling of 4p orbitals begins from GalZ =
31) (4s*3d4p) and
ds at Kr(Z= 36) (4s*3d 4p').
Fifth period
esponds to n =
5. It contai
fromRb(5s) to
(e(Ss'4d10sp). Afterthe
48) (5s4d.These ten
5p) and ends at XeZ =
54)(5s4dsp).
tains 9 orbitals i.e., one 5s, five 4d and three 5p orbitals. Therefore, fifth period has eighteen elements
filling of 5s orbital, the filling of 4d orbitals starts from Y{Z =
39) (4d'5s) and ends at
ese ten elements constitute the 4d transition series. Thereafter the filling of 5p orbitals begins at In(Z =
49)

3. p-BLOCK
s-BLOCK
13 14 15 16
18
2 17
1
He
Be d-BLOCK
2 BC NOF Ne
p ASi P s CAr
Li
3 4 6 9 10
Na Mg 12
TiVCMn Fe Co Ni Cu Z
3d Sc
4 KCa
S
4p Ga Ge As Se Br Kr
Y Zr Nb Mo Te
Ru Rh Pd Ag | Cca
4d
5s Rb
5d La
Hr Ta
WRe | Os Ir Pt
Au Hg
Sp In
Sn Sb Te I Xe
6s Cs Ba
6p T Pb Bi Po At Rn
Rf DbSg| Bh Hs
|Mt Ds
Rg Cn
Ra 6d Ac
7p
Nh Fl |Mc Lv
Ts Og
f-BLOCK
Lanthanoids
4f
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er
Tm Yb
Tm Yb Lu
Actinoids Th
U
Pa
Np Pu Am Cm Bk Cr Es Fm
No Lr
Md
s-Block elements
The general electronic configuration of s-block elements is ns, wheren represent the outermost shell. s-Block has two groups, group 1
elements (alkali metals) and group 2 elements (alkaline earth metals). The outer electronic configuration of group 1 and group 2 is
ns and ns respectively. s-Block elements are reactive metals.
General characteristics of s-block elements
) They are soft metals and have low melting and boiling points.
(i) They have largest atomic radii in their corresponding period.
(Gii) They have low ionisation energy.
(Giv) They are highly electropositive.
(v) They are highly reactive.
(vi) They are good conductors of heat and electricity.
(vi) The oxidation state shown by group 1 is +1 and by group 2 is +2.
(Vin)They impart characteristic colour to the flame except Be and Mg.
(ix) They have great affinity for oxygen and their oxides are basic in nature.
) Their hydroxides are strong alkalies.
(K0) Group 1 elements are called alkali metals because they react with water to form alkalies.
Kki) Fr and Ra are radioactive elements.
(xii)H is a gas.
Xiv)They are good reducing agents.
w lhey form ionic compounds, except lithium and beryllium, which form covalent compounds.
Xwi) They displace hydrogen from acids and form corresponding salts.
Due to their low ionisation energy, alkali metals like potassium, rubidium and caesium are used in phtoelectric cells.
P-Block elements
ck elements, last electron enters into any of the outermost p-orbital shell thus, the general electronic configuration ofp-block
elements is ns np.

4. t consists of six groups-group 13, 14, 15, 16, 17 and 18. Group15 elements are called pnictogens, group-16 elements ate ral.
chalcogens, group-17 ele
S-block and p-block elements are collectively called main or representative elements (except zero groupelements)
alled
ents are called halogens and group-18 elements are called noble gases.
General characteristics of p-block elements
) These include metals, metalloids and non-metals, the number of non-metals are much higher than metals and metalloids,
Gi) They show variable oxidation states except fluorine and noble gases.
Group 13 15 16 17 18
4
Oxidation states +3 +4 to-4 +5 to -3+6to -2 +7to -1 0
(ii) There is regular increase in non-metallic character from left toright
(iv) They form ionic as well as covalent compounds.
(They have relatively higher value of ionisation energy as compared to those ofs-block elements.
(vi) Halogens are strong oxidising agents.
(vi) Most of them are highly electronegative.
(vii)Mostly they form acidic oxides.
(0) Some p-block elements show allotropic property, for example, carbon, silicon, phosphorus,sulphur,etc.
(X)Some oftheseelements shows catenation, for example, carbon and silicon.
d-Block elements
In d-block elements, the last electron enters in (n-1d-subshe.Their general electronic configuration is represented as
n-11-10 ns-2, The d-block elements have valence electrons both in their outermost and second outermostpenutimateshell.Their
properties are intermediate between s-and p-block elements. Thus, these elements are called transition lements. These elements are
classied into four series, viz, 30, 4d, Sd and 6d series corresponding to the filing oforbitals of 30, 4d, Sd and 6d subshels of thid,
fourth, fifth and sixth energy shells, respectively. Each series consists of 10 elements in each.
3dseries: It contains ten elements from Sc (Z = 21) to Zn (Z = 30), in which 3d orbitals are progressively filled.
4dseries: It contains ten elements from Y(Z = 39) to Cd (Z = 48), in which 4d orbitals are progressively flled.
5d
series: It contains ten elements, La (7= 57) and from Hf(Z=72)to Hg (Z =80), in which 5d orbitals are progressiwelyfilld.
6d
series:t contains ten elements, Ac (Z= 89) and from Rf (Z = 104) to Cn (Z = 112), in which 6d orbitals are progressiwely filed.
General characteristics of d-block elements
() They all are metals.
(i) They have high melting and boiling points.
()Theyare hard, malleable and ductile
(iv) They have high tensile strength.
They are good conductors of heat and electricity.
(vi) They have high density.
(vi) They are more electropositive than p-block elements and less electropositive than s-blockelements
(vii)They showvariable oxidation states, e.g., Fe and Fe* etc.
(ix) They mostly form coloured compounds.
(x)Theyare paramagnetic in nature.
(Ki)They have hightendencyto form complex compounds.
(xii) They form both ionic and covalent compounds.
(xii) Most of them possess catalytic properties.
ransition elements must have incomplete penultimate d-subshell either in the neutral atom or in any one of its statbie
idation
slatesZn, Cd and
Hg which has stable completely flled d orbitals ie, (n -
1)ans? electronic configuration,donot
show
most of the properties of transition elements. Hence Zn, Cd and Hg are not considered as typical transition
e ti
Fundamental difference in the electronic configuration of representative elements andtransit
ition
elements inthe representative elements (s-and p-block elements), the valence electrons are present ony
outermostshellwhile in the transition elements, the valence electrons are present in the outermst shell as wel a
the
d-orbitals of penultimate shel.

5. -Block elements
In Ablock elements, last e
ilements, last electron enters into (n-2)/subshell.Their general electronicconfiquration is (n -2)/-14(n-
1)d-ns
ancicts of two series of elements placed at the bottom of the periodic table, these are called lanthanides, Ce (Z =
58) to
B711 and actinides Th (Z =
90) to Lr (Z =
103). Each series has 14elements.These are also known as inner-transition elements.
General characteristics of 1-block elements
0 All of these are metals.
i) In each series, properties of elements are quite similar,
The elements after uranium are man-made elements and are called transuranic elements.
ad Thev show variable oxidation states but the most stable and common oxidation state is +3.
()They
form colouredcompounds
(vi) They show paramagnetism.
(vi) They have tendency to form complexes.
(viLanthanoids are also known as rare earth elements.
Although thorium, Th (Z =
90) (5f° 6d 7s) does not have any electron in the 5/-orbital, yet it is considered to be a f-block
element since its properties resemble more with the f-block elements than the d-block elements.
ILLUSTRATIONS
Two elements X and Yhave atomic number 16 and 19 respectively.
)Write down the electronic configurations of Xand Y.
i) Which element belongs to s-block?
ii) Which element belongs to p-block?
Ans. 6) X: 1s2s 2p 3s 3p, Y:1s22s 2p 3s3p 4s
(ii) Ybelongs to s-block as the last electron enters in 4s orbital.
(ii) Xbelongs to p-block as the last electron enters in 3p orbital.
In
terms ofelectronicconfiguration, what the elements of a given group and period have in common?
Ans. For elements in a group, the number of electrons in the valence shell is same. For elements in a period, the number
of shells is same.
Metals, Non-metals and Metalloids
addition to displaying the classification of elements into s,p,d and -blocks, all the elements can be broadly classified as metals,
non-metals and metalloids based on their properties.
Metals
ESe are the elements which are electropositive in nature i.e., they have tendency to lose electrons. They are present on the left side
e periodic table. As we move from left to right in periodic table, metallic character decreases and on moving from top to bottom
metallic character increases. More than 78% of all known elements comprises metals.

6. General characteristics of metals
i) They are usually solid at room temperature except mercury which is liquid.
Gi) They have high melting and boiling points except Ga, Cs and Fr.
(in) They are good conductors of heat and electricity.
() They are malleable (can be flattened into thin sheets by hammering) and ductile (can be drawn intowires)
Non-metals
These are the elements which are electronegative in nature i.e., they have tendency to attract the shared pair of electrons. The nan.
metallic character increases as we move from left to right in periodic table and on moving from top to bottom non-metallic character
decreases. Non-metals are present on top right hand side of the periodic table. There are about 20% of ail known elements which are
non-metals. They are present in p-block.
General characteristics of non-metals
) They are usually solids or gases at room temperature except bromine which is a liquid.
Gi) They have low melting and boiling points except boron and carbon which have high melting and boiling points.
Gi) They are generally brittle and are neither malleable nor ductile.
(iv) They are poor conductors of heat and electricity.
Metalloids
These are the elements which show some properties of metals and some properties of non-metals. They are neither metals nor non-
metals:They are also known as semi-metals. Si, Ge, As, Sb, Te etc. are metalloids. They are present in p-block of periodic table at the
border between metals and non-metals.
General characteristics of metalloids
6) They behave as semi conductors i.e., they conduct electricity but not as well as metals do.
Gi) They are lustrous like metals and brittle like non-metals.
Position of an Element in Period, Group and Block of the Periodic Table
Period
The principal quantum number of the valence shell represents the period to which an element belongs.
Block
The type of orbital in which the differentiating electron enters, represents the block to which an element belongs.
Group
The group of an element can be predicted from the number of electrons in its valence she!ll or/and penultimate (next to outermost
ie., (n-1) shel) as given below:
For s-block elements: Group number =
Number of valence electrons
For p-block elements: Group number = 10 + Number of valence electrons
For d-block elements: Group number =
Number of valence electrons + Number of (n -1) d electrons
For f-block elements:Groupnumber =3
Merits of the long form of periodic table
0 The long form of periodic table is based upon the atomic number which is supposed to be the most fundamental property of an
element.
(i) It is easy to remember all the elements more easily in sequence of atomic numbers.
(1) The long form of periodic table is closely connected to the electronic confiquration of elements. Therefore, the position of an
element in the periodic table can easily be justified.
(V) The elements possessing similar type of electronic confiqurations and similar physical and chemical properties have been grouped
together into blocks (s, p, d and f-block). This simplifies the study of elements and their compounds.
Ihe
placement of isotopes of an element at the same place as the element in the periodic table is justified by the factthattney
pOssess similar atomic numbers and exhibit similar chemical properties but have different atomic masses.
(Vi) It explains the cause of periodicity on the basis of electronic configuration.
(vi) It also separate metals and non-metals.

7. Summary of Some General Trends
PERIOD
Increases
Decreases
lonisation enthalpy
Electropositive character
Metallic character
Non-metallic character
Reducing power
Atomic size
Electronegativity
Basic nature of oxides
DecreasesS
Increases
DecreasesS
Decreases
Increases
Decreases
Decreases
C
Basic nature of hydrides
wwW
Relations between different periodic properties
S.No. lonisation potential Electronaffinity Electronegativity Metallic character Basic character Acidic character
1
oc Atomic size c Atomic size Atomic size
Atomic size Atomicsize Atomicsize
1
Effective nuclear c Effective nudlear
Effective nuclear
charge
Effective nuclear
charge
2 o Effective nuclear Efective nuclear
charge
charge Charge
Charge
ac lonisation
potential
c lonisation
3 lonisation potential
Shielding effect Shielding effect potential lonisation potential
xStabilityoffulland 1/Stability offull oc S-character in
and half-filled
orbitals
aElectronegativity
4.
half-filled orbitals hybrid orbitals Electronegativity Electronegativity
oc Non-metallic
character
5. Penetrating c Metallic character
p-character in
hybrid orbitals
power
6. oOxidation c Oxidation oc Oxidation oc Oxidation
number number number Oxidation number number