ATOMIC
STRUCTURE
ATOMIC STRUCTURE
1.
2.
3.
4.
5.
Rutherford’s Experiment
Basic Particles of Atom
Atomic Number and Mass Number
Isotope, Isobar, Isotone, and Isoelectron
Electron Configuration and Valence
Electron
6. Development of Atomic Theory
1. RUTHERFORD’S EXPERIMENT
CONCLUSION:
 The atom consist of
nucleus which has
positive charge and the
mass of atom is
centered in the nucleus
 There are many
electrons which move
around nucleus outside
the nucleus and the
amount of electrons
equal to the charge of
nucleus, so the atom
has neutral
characteristic
1. RUTHERFORD’S EXPERIMENT
radium
Plumbum plate
 ray
gold
Detector (ZnS)
CONCLUSION:
 The atom consist of nucleus which has positive
charge and the mass of atom is centered in the
nucleus
 There are many electrons which move around
nucleus outside the nucleus and the amount of
electrons equal to the charge of nucleus, so the
atom has neutral characteristic
2. Basic Particles of Atom
ATOM
ELECTRON
PROTON
NUCLEUS
NEUTRON
3. Atomic Number and Mass
Number
A
Z
X
Explanation:
X : symbol of atom
A : mass number, shows the amount
of proton + neutron
Z : atomic number, shows the amount
of proton/electron
EXERCISE
Complete the table below!
Atomic
Number
Mass
Number
Proton
Neutron Electron
10
47
18
108
10
47
8
61
10
47
50
83
56
119
50
69
50
83
28
59
83
56
26
16
28
126
81
26
16
209
137
56
31
30
15
31
56
26
16
28
Symbol
18
10
108
47
119
50
209
83
137
56
56
26
31
16
59
28
Ne
Ag
Sn
Bi
Ba
Fe
S
Ni
IONIC REACTION
EQUATION
POSITIVE ION (KATION)
23
11
23
11
Na
Na

+ e
9
4
Be
9
4
Be
2
e = 11
e = 10
e=4
e=2
p = 11
p = 11
p=4
p=4
n = 12
n = 12
n=5
n=5
+ 2e
NEGATIVE ION (ANION)
35
17
Cl +
e
35
17
Cl

31
15
P + 3e
31
15
P
3
e = 17
e = 18
e = 15
e = 18
p = 17
p = 17
p = 15
p = 15
n = 18
n = 18
n = 16
n = 16
EXERCISE
Complete the table below!
Atom
Number
19
35
13
8
Mass
Number
39
80
27
16
Proton
19
35
13
8
Neutron
20
45
14
8
Electron
Symbol
18
39
19
36
80
35
10
10
27
13
16
8
K
Br
Al
O


3
2
4.
ISOTOPE
ISOBAR
ISOTONE
ISOELECTRON
ISOTOPE
DEFINITION OF ISOTOPE:
The atoms which have similar atomic number
but the mass number is different.
EXAMPLE:
35
17
Cl and
12
6
,
C
13
6
37
17
Cl
C and
14
6
C
ISOBAR
DEFINITION OF ISOBAR:
The atoms which have different atomic
number (the element is different) but the mass
number is same.
EXAMPLE:
14
7
24
11
N and
Na and
14
6
C
24
12
Mg
ISOTONE
DEFINITION OF ISOTONE:
The atoms which come from different element,
but the amount of neutron is same
EXAMPLE:
31
15
40
20
P and
Ca and
32
16
S
39
19
K
ISOELECTRON
DEFINITION OF ISOELECTRON:
The atoms which come from different element,
but the amount of electron is same
EXAMPLE:
27
13
Al
3
,
16
8
O
2-
and
20
10
Ne
p = 13
p=8
p = 10
n = 14
n=8
n = 10
e = 10
e = 10
e = 10
5.
Electron Configuration
and
Valence Electron
ELECTRON
CONFIGURATION
•
•
•
•
An electron configuration is the spreading of the electron in
shells of an atom. The configuration must follow the
regulations below:
The maximum quantity of electron in the shell is 2n2
n Value of K shell = 1, so, the max. quantity of electron =2
n Value of L shell = 2, so, the max. quantity of electron = 8
n Value of M shell = 3, so, the max. quantity of electron =18
etc.
The maximum quantity of electrons in the external shell is 8
Normally, the filling of electrons starts at the inner shell (K).
Elements with atom number 1 to 18, is filled with electrons
in their external shell only if the inner shell is full.
The elements with atomic number more than 18, the
external shell, which is the fourth shell (N) and other shell
levels, can be filled with electrons, even though the third
shell (M) has not full yet.
EXERCISE
COMPLETE THE TABLE BELOW!
Atom
Electron Skin
K
L
M
3Li
2
12Mg
2
2
31Ga
50Sn
2
2
1
8
8
33As
2
52Te
35Br
86Rn
2
8
8
8
18
18
18
18
2
2
8
8
18
18
N
O
P
3
18
4
5
18
6
7
32
18
8
Q
VALENCE ELECTRON
1.
2.
3.
Valence electron is the quantity of electron on the
external shell of which the maximum quantity is 8.
Example:
11 Na
Electron configuration: 2 8 1
Quantity of valence electron: 1
20 Ca
Electron configuration: 2 8 8 2
Quantity of valence electron: 2
54 Xe
Electron configuration: 2 8 18 18 8
Quantity of valence electron: 8
6. Development of
Atomic Theory





Atomic theory of Dalton
Atomic theory of J.J. Thomson
Atomic theory of Rutherford
Atomic theory of Niels Bohr
Modern atom theory
ATOMIC THEORY OF DALTON
• A substance consist of minute
particles that can’t be divided, and
this is called an atom with a small
massive ball shape
• Atoms of an element are identical
but they are different from atoms
of the other elements
• Chemically, atoms are interwoven to
each other to perform a molecule
with a simple comparison
Atom model of Dalton
• A compound is the product of the
reaction of atom
• An atom of an element is permanent,
can’t de divided or created or
destroyed
ATOM THEORY OF J.J.
THOMSON
Cloud of proton
electron
-
-
-
-
Atom model of J.J. Thomson
Negative charged
electrons spread
inside the positive
charged ball (looks
like the currants that
spread over a piece
of cake, so, its called
COOKIE THEORY)
ATOM THEORY OF RUTHERFORD
 All of positive charge and most of atom
mass are concentrated at a particle at
the center of the atom. This particle is
the nucleus of an atom.
electron  Some light electrons that can’t
restrained the high speed of alpha
Skin of atom
particles go around the nucleus like
planets that orbit to the sun.
 An atom is neutral, meaning that in an
n atom, the charge of the electrons
u (negative) is equal with the charge of
+
c the nucleus (positive)
Unfortunately Rutherford can’t
l
explain, why an electron can’t attach
e
to the nucleus. Each of them have
u different charges, an electrons will
Atom model of
s attach to the nucleus in a spiral orbit
Rutherford
track and then hits the nucleus.
Atom radius
ATOM THEORY OF
NIELS BOHR
1.An atom consist of a nucleus (positive) that
is surrounded by electrons (negative)
2. An electron goes around the nucleus in a
given orbit known as stationary energy. This
is called the major energy level or the major
quantum number.
3. If an electron stays on its stationary
energy level, there will be no ray sparks.
4. An electron can move to the upper level if
it absorbs an energy, and an electron can
move to the lower level if it releases some of
its energy.
THAT’S ALL
Periodic table of elements-2