ch 1

1. Standard 10 Chapter Periodic Table
Standard 10 Chapter Periodic Table
Gurudatta K Wagh
Gurudatta K Wagh

2. Dobereiner's Triads
Triads Groups of three elements which showed
similar properties
Atomic mass of the middle element is
approximately the mean of the atomic masses
of other two elements
Dobereiner's Triads
Triads Groups of three elements which showed
similar properties
Atomic mass of the middle element is
approximately the mean of the atomic masses
of other two elements
Element Atomic mass
Li 6.9
Na 23
K 39
Standard 10 Chapter Periodic Table
Standard 10 Chapter Periodic Table
In the triad of Li, Na and K the
atomic mass of Na (23) is the
mean of the atomic masses of
Li and K
6.9 + 39 = 45.9 ÷ 2 = 22.95
In the triad of Li, Na and K the
atomic mass of Na (23) is the
mean of the atomic masses of
Li and K
6.9 + 39 = 45.9 ÷ 2 = 22.95
Johann
Wolfgang
Dobereiner
Johann
Wolfgang
Dobereiner

3. Element Atomic mass
Li 6.9
Na 23
K 39
Ca 40.1
Sr 87.6
Ba 137.3
Cl 35.5
Br 79.9
I 126.9
S 32
Se 79
Te 128
Features
Only a few triads could be
identified
System of triads could not
continue
Features
Only a few triads could be
identified
System of triads could not
continue

4. Newland’s Octaves
Fifty-six elements were discovered
Newlands arranged them in the increasing order of
their atomic masses
Every eighth element had properties similar to the
first
Compared them with the octaves in music
Newland’s Octaves
Fifty-six elements were discovered
Newlands arranged them in the increasing order of
their atomic masses
Every eighth element had properties similar to the
first
Compared them with the octaves in music
John Alexander
Reina Newlands
John Alexander
Reina Newlands
Seven musical
notes
Indian
sa, re, ga, ma, pa,
da, ni
Western
do, re, mi, fa, so,
la, ti
Seven musical
notes
Indian
sa, re, ga, ma, pa,
da, ni
Western
do, re, mi, fa, so,
la, ti

5. Features
Out of the 56 elements, elements up to Ca could
be arranged
After Ca every eighth element did not possess
properties similar to the first
To fit the existing elements two elements were
placed in the same position which differed in their
properties
Inert (noble) gases were not included because
they were not discovered
Features
Out of the 56 elements, elements up to Ca could
be arranged
After Ca every eighth element did not possess
properties similar to the first
To fit the existing elements two elements were
placed in the same position which differed in their
properties
Inert (noble) gases were not included because
they were not discovered

6. Dmitri Ivanovich
Mendeleev
Dmitri Ivanovich
Mendeleev
Mendeleev’s Periodic Table
Examined the relationship between
the atomic masses of elements and
their physical and chemical
properties
Mendeleev’s Periodic Table
Examined the relationship between
the atomic masses of elements and
their physical and chemical
properties
Chemical properties Concentrated on the
compounds formed by the elements with oxygen
and hydrogen as they were very reactive
Believed that atomic mass was the most
fundamental property in classifying the elements
Chemical properties Concentrated on the
compounds formed by the elements with oxygen
and hydrogen as they were very reactive
Believed that atomic mass was the most
fundamental property in classifying the elements

7. Arranged elements in the increasing order of their
atomic masses in horizontal rows till he came
actoss an element which had properties similar to
the first
He placed this element below the first element and
thus started the second row of elements
Created the first periodic table containing 63
elements known
Arranged elements in the increasing order of their
atomic masses in horizontal rows till he came
actoss an element which had properties similar to
the first
He placed this element below the first element and
thus started the second row of elements
Created the first periodic table containing 63
elements known

8. Mendeleev’s Periodic Table
The tabular arrangement of the elements based on
the periodic law
Mendeleev’s Periodic Table
The tabular arrangement of the elements based on
the periodic law
Mendeleev’s
Periodic Law
The physical and
chemical
properties of
elements are a
periodic function
of their atomic
masses
Mendeleev’s
Periodic Law
The physical and
chemical
properties of
elements are a
periodic function
of their atomic
masses

9. Features
Periods
Horizontal rows, numbered 1 to 7
Properties of elements in a period show regular
gradation from left to right
Groups
Vertical columns, numbered I to VIII. I to VII are
further divided into A and B subgroups
Features
Periods
Horizontal rows, numbered 1 to 7
Properties of elements in a period show regular
gradation from left to right
Groups
Vertical columns, numbered I to VIII. I to VII are
further divided into A and B subgroups

10. Demerits
H resembles alkali metals and halogens. No fixed
position could be given to H
Isotopes of same elements have different atomic
masses. Each of them should be given a different
position. As isotopes are chemically similar, they
were given same position
Co with higher atomic mass (58.93) is placed
before Ni (58.71)
Mn is placed with halogens which totally differ in
the properties
Demerits
H resembles alkali metals and halogens. No fixed
position could be given to H
Isotopes of same elements have different atomic
masses. Each of them should be given a different
position. As isotopes are chemically similar, they
were given same position
Co with higher atomic mass (58.93) is placed
before Ni (58.71)
Mn is placed with halogens which totally differ in
the properties

11. Merits
Successful classification of all known elements
Some vacant/ blank spaces were left for elements
yet to be discovered
Mendeleev predicted properties of these elements
even before they were discovered
Later they were found to be correct
Noble gases were discovered later and placed in
the table without disturbing the positions of other
elements
Merits
Successful classification of all known elements
Some vacant/ blank spaces were left for elements
yet to be discovered
Mendeleev predicted properties of these elements
even before they were discovered
Later they were found to be correct
Noble gases were discovered later and placed in
the table without disturbing the positions of other
elements

12. Modern Periodic Table
Atomic number is the most fundamental
property of an element and not its
atomic mass – Henry Moseley
Modern Periodic Table
Atomic number is the most fundamental
property of an element and not its
atomic mass – Henry Moseley
Henry
Gwyn
Jeffreys
Moseley
Henry
Gwyn
Jeffreys
Moseley
Atomic number (Z) = number of protons in the
nucleus of the atom
Also represents number of electrons in the outer
shell
Atomic number (Z) = number of protons in the
nucleus of the atom
Also represents number of electrons in the outer
shell

13. Mendeleev’s Periodic Law was modified into
Modern Periodic Law
The chemical and physical properties of elements
are a periodic function of their atomic numbers
Modern Periodic Table = Long Form of Modern
Periodic Table
Not much different from Mendeleev’s Periodic
Table
Mendeleev’s Periodic Law was modified into
Modern Periodic Law
The chemical and physical properties of elements
are a periodic function of their atomic numbers
Modern Periodic Table = Long Form of Modern
Periodic Table
Not much different from Mendeleev’s Periodic
Table

14. Discovery and Assignment of Elements with Atomic Numbers 113, 115, 117
and 118
IUPAC announces the verification of the discoveries of four new chemical
elements: The 7th period of the periodic table of elements is complete.
Update 21 Jan 2016: Technical Reports available
The fourth IUPAC/IUPAP Joint Working Party (JWP) on the priority of claims to the
discovery of new elements has reviewed the relevant literature for elements 113,
115, 117, and 118 and has determined that the claims for discovery of these
elements have been fulfilled, in accordance with the criteria for the discovery of
elements of the IUPAP/IUPAC Transfermium Working Group (TWG) 1991 discovery
criteria. These elements complete the 7th row of the periodic table of the
elements, and the discoverers from Japan, Russia and the USA will now be invited
to suggest permanent names and symbols. The new elements and assigned
priorities of discovery are as follows:
Element 113 (temporary working name and symbol: ununtrium, Uut)
Elements 115, 117, and 118 (temporary working names and symbols:
ununpentium, Uup; ununseptium, Uus; and ununoctium, Uuo)
http://www.iupac.org/news/news-detail/article/discovery-and-assignment-of-elements-with-atomic-numbers-113-115-117-and-118.html

17. Position of elements in the Modern Periodic Table
Periods (number of shells)
Horizontal rows, Seven, numbered 1-7
Elements in the same period have same number of
shells which is equal to the period number. E.g.
Period 7 has 7 Shells
In each period a new shell starts filling up
Position of elements in the Modern Periodic Table
Periods (number of shells)
Horizontal rows, Seven, numbered 1-7
Elements in the same period have same number of
shells which is equal to the period number. E.g.
Period 7 has 7 Shells
In each period a new shell starts filling up

18. Period
no.
Size Elements
1 shortest 2
2 short 8
3 short 8
4 long 18
5 long 18
6 longest 32
7 incomplete see box
*IUPAC announces the verification of the discoveries of four new chemical
elements: The 7th period of the periodic table of elements is complete.
Update 21 Jan 2016: Technical Reports available
http://www.iupac.org/news/news-detail/article/discovery-and-assignment-of-elements-with-atomic-numbers-113-115-117-and-118.html
*Temporary
working names
and symbols
113 ununtrium,
Uut
115 ununpentium,
Uup
117 ununseptium,
Uus
118 ununoctium,
Uuo

19. Groups (number of valence electrons)
Vertical columns, Eighteen, numbered 1-18
Elements in the same group have
•same number of valence electrons/ same outer
electronic configuration,
•show same chemical properties
Group 1, alkali metals
Group 2, alkaline earth metals
Group 17, halogens
Group 18, inert/ noble gases
Groups (number of valence electrons)
Vertical columns, Eighteen, numbered 1-18
Elements in the same group have
•same number of valence electrons/ same outer
electronic configuration,
•show same chemical properties
Group 1, alkali metals
Group 2, alkaline earth metals
Group 17, halogens
Group 18, inert/ noble gases

20. Metals – left hand side
Non-metals – right hand side
Normal elements – Groups 1, 2 and Groups 13-17.
One outermost shell incomplete
Transition elements – Groups 3-12. Two outermost
shells incomplete
Inert gases – Outermost shell contains 8 electrons
Metals – left hand side
Non-metals – right hand side
Normal elements – Groups 1, 2 and Groups 13-17.
One outermost shell incomplete
Transition elements – Groups 3-12. Two outermost
shells incomplete
Inert gases – Outermost shell contains 8 electrons

21. Group no. 1 2 3-4-5-6-7-8-9-10-
11-12
13-14-15-
16
17 18
Type Alkali
metals
Alkaline
earth
metals
Transition
elements
Non-
metals,
metalloids,
metals
Halogens Inert or
noble
gases
Normal elements Normal elements

22. Inner transition – at the bottom, contain two
series, viz. lanthanides, actinides
Lanthanides (Ce – Lu) – 14 elements, atomic
numbers 58-71. Placed along with La (57), Group 3,
Period 6. Close resemblance in properties to La
Actinides (Th – Lr) – 14 elements, atomic numbers
90-103. Placed along with Ac (89), Group 3, Period
7. Close resemblance in properties to Ac
Inner transition – at the bottom, contain two
series, viz. lanthanides, actinides
Lanthanides (Ce – Lu) – 14 elements, atomic
numbers 58-71. Placed along with La (57), Group 3,
Period 6. Close resemblance in properties to La
Actinides (Th – Lr) – 14 elements, atomic numbers
90-103. Placed along with Ac (89), Group 3, Period
7. Close resemblance in properties to Ac
Group 3
Period 6 Lanthanides 14 elements
Period 7 Actinides 14 elements

23. Classification of elements as per electronic configuration
Four blocks s, p, d, f
s-block Metals, Groups 1, 2. 1 or 2 electrons in outermost
shell, normal elements
p-block Metals, non-metals, metalloids, Groups 13-18. 3-8
electrons in outermost shell, normal elements except
Group 18
d-block Transition elements/ metals, Groups 3-12. Two
outermost shells incomplete
f-block Inner transition elements/ metals, at the bottom,
lanthanides, actinides
Classification of elements as per electronic configuration
Four blocks s, p, d, f
s-block Metals, Groups 1, 2. 1 or 2 electrons in outermost
shell, normal elements
p-block Metals, non-metals, metalloids, Groups 13-18. 3-8
electrons in outermost shell, normal elements except
Group 18
d-block Transition elements/ metals, Groups 3-12. Two
outermost shells incomplete
f-block Inner transition elements/ metals, at the bottom,
lanthanides, actinides

25. Group/s 1-2 3-12 13-18 3
Block s
Metals
d
Transition
elements/
metals
p
Metals,
Non-
metals,
metalloids
f
Inner transition
elements/ metals
Lanthanides
(Period 6)
Actinides
(Period 7)
Electrons in
outermost
shell
1, 2 2 outermost
shells
incomplete
3-8 2 outermost
shells incomplete

26. Merits
Modern Periodic Table (atomic number) versus
Mendeleev’s Periodic Table (atomic mass)
All isotopes of the same elements have different
masses but same atomic number and occupy the
same position
Anomaly regarding Co (27) and Ni (28) disappears
Classification of elements into blocks based on their
electronic configuration
Merits
Modern Periodic Table (atomic number) versus
Mendeleev’s Periodic Table (atomic mass)
All isotopes of the same elements have different
masses but same atomic number and occupy the
same position
Anomaly regarding Co (27) and Ni (28) disappears
Classification of elements into blocks based on their
electronic configuration

27. Periodic properties
Properties show gradual variation in a group and in
a period
Properties repeat after a certain interval of atomic
number
Valency
Number of valence electrons in the outermost shell
In a group all the elements have the same valency
Increases from 1 to 4 for the periods 2, 3 and
decreases from 4 to 0 left to right
Periodic properties
Properties show gradual variation in a group and in
a period
Properties repeat after a certain interval of atomic
number
Valency
Number of valence electrons in the outermost shell
In a group all the elements have the same valency
Increases from 1 to 4 for the periods 2, 3 and
decreases from 4 to 0 left to right

28. Atomic size
Determined using atomic radius
Atomic radius is the distance between the centre of
atom and the outermost shell
Atomic radius decreases from left to right in a
period because electrons are added to same shell
and experience greater pull from the nucleus
Atomic radius increases from top to bottom in a
group because new shells are added, thereby
pushing outermost electrons farther from the
nucleus
Atomic size
Determined using atomic radius
Atomic radius is the distance between the centre of
atom and the outermost shell
Atomic radius decreases from left to right in a
period because electrons are added to same shell
and experience greater pull from the nucleus
Atomic radius increases from top to bottom in a
group because new shells are added, thereby
pushing outermost electrons farther from the
nucleus

29. Atomic
radius
Atomic
radius
P
e
r
i
o
d
Atomic radius
decreases from left
to right
Ooo
electrons are added to the same shell and
experience greater pull from the nucleus
Group O
O
O
Atomic radius increases from top to bottom
new shells are added, thereby pushing outermost electrons
farther from the nucleus

30. Metallic and non-metallic properties
Metals – tendency to lose electrons, electropositive
Non-metals – tendency to accept/ share electrons,
electronegative
Because atomic size decreases and electrons are not
easily released
•Metallic character – decreases left to right in a period
•Non-metallic character – increases left to right in a period
In the group, on the right side, lower members are non-
metals and higher members are metals
Metallic and non-metallic properties
Metals – tendency to lose electrons, electropositive
Non-metals – tendency to accept/ share electrons,
electronegative
Because atomic size decreases and electrons are not
easily released
•Metallic character – decreases left to right in a period
•Non-metallic character – increases left to right in a period
In the group, on the right side, lower members are non-
metals and higher members are metals

31. Because atomic size increases and valence
electrons can be easily removed
•In a group, metallic character increases and non-
metallic character decreases from top to bottom
•Group 14 First element is C, non-metal, next two Si
and Ge are metalloids, Sn and Pb are metals
A zig-zag line separates metals from non-metals
Borderline elements B, Si, Ge, As, Te, Po show
intermediate properties – metalloids/ semi-metals
Because atomic size increases and valence
electrons can be easily removed
•In a group, metallic character increases and non-
metallic character decreases from top to bottom
•Group 14 First element is C, non-metal, next two Si
and Ge are metalloids, Sn and Pb are metals
A zig-zag line separates metals from non-metals
Borderline elements B, Si, Ge, As, Te, Po show
intermediate properties – metalloids/ semi-metals

32. THANK YOU
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Textbook
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