ATOMIC STRUCTUR
E
ATOMIC STRUCTURE1. Rutherford’s Experiment2. Basic Particles of Atom3. Atomic Number and Mass Number4. Isotope, Isobar, Isotone, and
Isoelectron5. Electron Configuration and
Valence Electron6. Development of Atomic Theory
1. RUTHERFORD’S EXPERIMENTCONCLUSION: 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
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
radium
Plumbum plate
ray
gold
Detector (ZnS)
1. RUTHERFORD’S EXPERIMENT
2. Basic Particles of Atom
ATOM
ELECTRON
NEUTRON
NUCLEUS
PROTON
3. Atomic Number and Mass Number
Explanation:X : symbol of atomA : mass number, shows the amount of proton + neutronZ : atomic number, shows the
amount of proton/electron
XAZ
EXERCISEComplete the table below!
Atomic Number
Mass Number
Proton Neutron Electron Symbol
Ne181010 1081018Ag108
4747 476147108
28
1626
56
83
50
59
31
56
137
209
119
28
16
26
56
83
50
31
1530
81
126
69
28
16
26
56
83
50
Ni5928
S3116
Fe5626
Ba13756
Bi20983
Sn11950
IONIC REACTION EQUATION
Na2311 + e
e = 11
p = 11
n = 12
Na2311
Cl3517
Cl3517+ e
e = 17
p = 17
n = 18
e = 10
p = 11
n = 12
e = 18
p = 17
n = 18
POSITIVE ION (KATION) Be9
429
4Be + 2e
e = 2
p = 4
n = 5
e = 4
p = 4
n = 5
P3115 + 3e331
15P
e = 15
p = 15
n = 16
e = 18
p = 15
n = 16
NEGATIVE ION (ANION)
EXERCISEComplete the table below!
Atom Number
Mass Number
Proton Neutron Electron Symbol
K3919
2168O
32713Al
Br8035
19 18201939
8
13
35
16
27
80 35
13
8 8
14
45
10
10
36
4.ISOTOPEISOBAR
ISOTONE ISOELECTRON
ISOTOPEDEFINITION OF ISOTOPE:
The atoms which have similar atomic number but the mass number is different.
EXAMPLE:
Cl3517 Cl37
17and
C126 C136 C146and,
ISOBARDEFINITION OF ISOBAR:
The atoms which have different atomic number (the element is different) but the mass number is same.
EXAMPLE:
N147 C146and
Na2411 Mg24
12and
ISOTONEDEFINITION OF ISOTONE:
The atoms which come from different element, but the amount of neutron is same
EXAMPLE:
P3115 S3216and
Ca4020 K3919and
ISOELECTRONDEFINITION OF ISOELECTRON:
The atoms which come from different element, but the amount of electron is same
EXAMPLE:
32713Al Ne20
10and, -2168O
p = 13
n = 14
e = 10
p = 8
n = 8
e = 10
p = 10
n = 10
e = 10
5. 5. Electron Electron
Configuration Configuration and and
Valence ElectronValence Electron
ELECTRON ELECTRON CONFIGURATIONCONFIGURATION
An electron configuration is the spreading of the electron An electron configuration is the spreading of the electron in shells of an atom. The configuration must follow the in shells of an atom. The configuration must follow the regulations below:regulations below:
• The maximum quantity of electron in the shell is The maximum quantity of electron in the shell is 2n2n22
n Value of K shell = 1, so, the max. quantity of electron =n Value of K shell = 1, so, the max. quantity of electron =n Value of L shell = 2, so, the max. quantity of electron =n Value of L shell = 2, so, the max. quantity of electron =n Value of M shell = 3, so, the max. quantity of electron =n Value of M shell = 3, so, the max. quantity of electron =etcetc..
• The maximum quantity of electrons in the external shell The maximum quantity of electrons in the external shell is is 88
• Normally, the filling of electrons starts at the inner shell Normally, the filling of electrons starts at the inner shell (K). Elements with atom number 1 to 18, is filled with (K). Elements with atom number 1 to 18, is filled with electrons in their external shell only if the inner shell is electrons in their external shell only if the inner shell is full.full.
• The elements with atomic number more than 18, the The elements with atomic number more than 18, the external shell, which is the fourth shell (N) and other external shell, which is the fourth shell (N) and other shell levels, can be filled with electrons, evenshell levels, can be filled with electrons, even though the though the third shell (M) has not full yet.third shell (M) has not full yet.
2818
EXERCISEEXERCISECOMPLETE THE TABLE BELOW!COMPLETE THE TABLE BELOW!
AtomAtomElectron SkinElectron Skin
KK LL MM NN OO PP QQ
33LiLi
1212MgMg
3131GaGa
5050SnSn
3333AsAs
5252TeTe
3535BrBr
8686RnRn
2
2
2
2
2
2
2
2
1
8
8
8
8
8
8
8
2
3
18 18 4
18 5
18 18 6
18 7
18 32 18 8
18
VALENCE ELECTRONVALENCE ELECTRON Valence electron is the quantity of electron on the Valence electron is the quantity of electron on the
external shell of which the maximum quantity is 8.external shell of which the maximum quantity is 8.Example:Example:
1.1. 1111 Na Na
Electron configuration: 2 8 1Electron configuration: 2 8 1Quantity of valence electron: Quantity of valence electron: 11
2.2. 2020 Ca Ca
Electron configuration: 2 8 8 2Electron configuration: 2 8 8 2Quantity of valence electron: Quantity of valence electron: 22
3.3. 5454 Xe Xe
Electron configuration: 2 8 18 18 8Electron configuration: 2 8 18 18 8Quantity of valence electron: Quantity of valence electron: 88
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
• 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 model of Dalton
ATOM THEORY 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 model of J.J. Thomson
electron
Cloud of proton
--
-
--
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.
Some light electrons that can’t restrained the high speed of alpha particles go around the nucleus like planets that orbit to the sun.
An atom is neutral, meaning that in an atom, the charge of the electrons (negative) is equal with the charge of the nucleus (positive)
Unfortunately Rutherford can’t explain, why an electron can’t attach
to the nucleus. Each of them have different charges, an electrons will
attach to the nucleus in a spiral orbit track and then hits the nucleus.
Atom model of
Rutherford
+
-
Skin of atom
electron
Atom radius
nucleus
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