Download appendix: 2 - Shodhganga

APPENDIX: 2
CONTENT ANALYSIS
CHAPTER: 1
QUANTUM MECHANICAL MODEL OF ATOM
AND QUANTUM NUMBERS
Atomic structure
Atomic hypothesis suggested by the chemists of 19th century.
1. An atom cannot be subdivided.
2. Atoms can be neither created nor destroyed.
3. Atoms of the same elements are alike.
4. Atoms of different elements are not alike; in particular their masses
are different.
Constituents of an atom
The most important constituents of an atom are electrons, protons,
and neutrons.
Neilsbohr atomic structure of hydrogen atom
Electrons in an atom have only certain stationary states. At this state
an electron emits no radiation.
Dual characters of light
The dual characters of light are as both waves and particles.
Debroglie’s equation
Debroglie proposed from his mathematical theory that the
wavelengths X should be related to the momentum (p) by the equation.
X = h/p
Werner heisenberg uncertainty principle
According to this principle it is not possible to determine the
position and momentum of body to an arbitrary accuracy.
AX x AP > h/4ji
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Atomic orbitals
The region of space around the nucleus when probability of finding
an electron is maximum. This region is called atomic orbital.
Quantum numbers
Quantum number describes energy, shape and orientation of orbital.
It is necessary to locate an electron in an atom, which is called quantum
numbers.
Types of quantum number
Principle quantum number ‘n’
Azimuthual quantum number T
Magnetic quantum number ‘m’
Spin quantum number ‘s’
Principle quantum number - It describes the energy of an electron.
Azimuthual quantum number - It determines the shape of the orbital in
which the electron is located.
Magnetic quantum number - It determines the orientation of electron
cloud in a particular sub shell.
Spin quantum number - It determines the direction of electron spinning.
CHAPTER: 2
ELECTRONIC
CONFIGURATION
SHAPES OF ORBITAL
AND
Paulins exclusion principle
Paulin’s exclusion principle is that it is not possible to accommodate
more than two electrons in an orbit.
Hund’s rule
Electron pairing in many orbital is not possible until all the available
orbital of a given sub shell contain one electron each.
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The filling up of orbital with the electron in the ground state of
the atom is governed by the following rules:
Rule 1
Occupation of orbital by electron
The electron are added one by one to various orbital as we move
from one element to the next in the order of increasing atomic number.
Rule 2
The orbital with a lower energy is filled up first before the filling up
of the orbital with the higher energy commences. (Aufbau Principle)
Rule 3
Electron pairing in any orbital is not possible until all die available
orbital of given sub shell contain one electron in each. (Hund’s rule)
Rule 4
An oribital cannot contain more than two electrons.
(Paulin’s
Exclusion Principle)
Rule 5
Electron prefers to enter those sub shells, which thereby get either
completely filled or just half- filled.
Rule 6
Half filled orbitals are more stable than partially filled orbital.
Similarly completely filled orbitals are more stable than incomplete orbital.
Shapes of ‘s’ orbital
‘S’ orbital can have only one possible orientation it should be
spherical in shape.
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Shapes Of‘P’ Orbital
‘P’ orbital are oriented along three mutually right angled axes i.e. Px
,Py, & Pz. They look like a dumb-bell shape.
CHAPTER; 3
PERIODIC CLASSIFICATION OF ELEMENTS
Periodic Classification Of Elements
Elements are arranged in the periodic table based on their physical
and chemical properties. Mendelef gave a final shape to the elements.
MendelefPs Periodic Law
The elements are arranged in the increasing order of their atomic
weight properties are repeated at regular intervals.
Modern Periodic Classification
According to modem periodic law, “ The physical and chemical
properties of the elements are the periodic functions of their atomic
number”
Groups & Periods
The elements arranged in the vertical columns are called groups.
The elements arranged in the horizontal rows are called periods.
Periods In The Periodic Table
Period 1
contains Hydrogen and Helium, which has 1 s orbital.
Period 2
commences with Lithium and ends with Neon have 2s
orbital.
Period 3
commences with Sodium and ends with Argon have 3 s
orbital.
Period 4
commences with Potassium and ends with Krypton
have 4s orbital.
Period 5
commences with Rubedium and ends with Xenon have
5s orbital.
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Period 6
CHAPTER: 4
commences with Caesium and ends with radon have 6s
orbital and also it includes lanthanide series along with
5d orbital.
TYPES OF ELEMENTS IN THE PERIODIC
TABLE
Period 7
It containing incomplete actinide series. It also
contains the newly discovered elements to honor the names of scientists
and places of scientific importance. Elements namely Mendelivium,
Rutherfardium, Bohrium etc.
Classification Of Elements
1. Noble gases
2. S and P block elements (Representative elements)
3. d block elements (Transition series)
4. f block elements (Inner Transition elements)
Noble Gases
Noble gases have ns2 np6 electronic configuration in the outermost
shell, except helium, which has got Is2 configuration in the outermost shell.
Noble gases, all the orbital are completely filled and hence electrons
cannot be neither easily added to them nor removed from them.
S and P Block Elements
The elements of group 1, group2, and groups 13 to 17 constitute
representative elements. The outermost electronic configuration changes
from ns1 to ns2 np5.
S- Block Elements
The groups 1st and 2nd with ns1 and ns2 configuration are known as Sblock elements.
P- Block Elements
The groups 13 to 17 with ns2 np1-5 are P-block elements.
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Valence Shell Electron
The number of valence shell electron for groups 1 and 2 is the same
as for groups 13 to 17. This number is obtained by subtracting 10 from the
group number.
Number of valence shell electron = Group Number-10.
D - Block Elements (Transition Elements)
The groups 3 to 12 with (n-1) d (1'10) n s (1‘2) are d-block elements.
They all are metals.
F- Block Elements (Inner Transition Elements)
The two rows of elements at the bottom of periodic table called the
lanthanide and actinides series are collectively called f-block elements.
Electronic Configuration
The electronic configuration of f-block element is
ls22s22p63s23p63d104s24p64d104fl
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