11th Chemistry Periodic Properties.pdf

periodic properties class 12

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
non metal
solid metal
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
cipal energy
level (n
The
peniod
ndicates
the value of n for the outermost shell.
aNailable
in
the
enero
Period
next hugther,
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
Second
2+6 8
Thiro
4 4s 3d 4p
2+ 10+6 18
2 +10 +6 18
2+ 14+ 10 +6 32
fourth
5s 4d 5p
Fifth
6 6s 4f 5d 6p Long period Sixth
7 7s 5f 6d 7p Longest period
2+14+
10+6 32
Incomplete period
Seventh
Fist period
responds to n
=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.
Thus
there
are only
H He
1s 1s2
Second period
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
period
is as follows
Li Be B
C N 0
25 25 25 2p 252p| 2 2p| 2s 2p 26 2p 25205
Ne
h al these elements, inner orbital i.e., 1s is completely filled.
Third period
t coresponds
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 K and L shells 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 3d orbitals. The 4s orbital has lower energy than 3d therefore,
st and then flling occurs of 3d and 4p orbitals. So, in fourth period, there are eighteen elements from K[{4s') to Kr(4s
As is flled
4p"). After filing of 4s o
orbital, the filling of five 3d orbitals begins since the energy of 3d orbitals is lower than those of 4p orbitals
ends at Vi2s 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 from Rb(5s) to
(e(Ss'4d10sp). After the
48) (5s 4d. These ten
5p) and ends at XeZ
= 54) (5s 4dsp).
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. Group 15 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 group elements)
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+6 to -2 +7 to -1 0
(ii) There is regular increase in non-metallic character from left to right
(iv) They form ionic as well as covalent compounds.
(They have relatively higher value of ionisation energy
as compared
to those of s-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 of these
elements 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 outermost penutimate shell. 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 of orbitals of 30, 4d, Sd and 6d subshels of thid,
fourth, fifth and sixth energy shells, respectively. Each series consists of 10 elements in each.
3d series: It contains ten elements from Sc (Z = 21) to Zn (Z = 30), in which 3d orbitals are progressively filled.
4d series: 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.
()They are 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-block elements
(vii) They show variable
oxidation states, e.g., Fe
and Fe* etc.
(ix) They mostly form coloured compounds.
(x)They are paramagnetic in nature.
(Ki)They have high tendency to 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
slates Zn,
Cd and
Hg which
has stable
completely flled d orbitals ie, (n
-1)ans? electronic configuration, do not
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 and transit
ition
elements in the representative elements (s-and p-block elements), the valence electrons are present ony
outermost shell while 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 electronic confiquration 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 14
elements. 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
coloured compounds
(vi) They
show paramagnetism.
(vi) They have tendency to form complexes.
(vi Lanthanoids 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
Y have atomic number 16 and 19
respectively.
)Write down the electronic configurations of X and Y.
i) Which element belongs to s-block?
ii) Which element belongs to p-block?
Ans. 6) X: 1s 2s 2p 3s 3p, Y:1s2 2s 2p 3s 3p 4s
(ii) Y belongs to s-block as the last electron enters in 4s orbital.
(ii) X belongs to p-block as the last electron enters in 3p orbital.
In terms of electronic configuration, 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 into wires)
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: Group number =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
fact that
tney
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 Electron affinity
Electronegativity
Metallic character Basic character Acidic character
1
oc Atomic size c Atomic size
Atomic size
Atomic size Atomic size
Atomic size
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
xStability of full and 1/Stability of full
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