2. • Matter are made up of tiny &
discrete particles
• Size of particles are very
minute ~~ 1x 10-7cm
3. Consist of atoms, molecules
ions Next
3. Let’s see the particles in
bromine liquid
Particle theory
4. The smallest particle of an element
and not breakable anymore.
Examples:
Atom of hydrogen
atom of magnesium
atom of oxygen
atom of chlorine
H
Mg
Cl
O
Particle theory
5. A group of two or more
atoms, which might consist
of:
one type of element (Element)
Or different types of
element (Compound)
6. Examples of element molecules:
Molecule of hydrogen gas
Molecule of oxygen gas
Molecule of chlorine gas
7. Ions are atoms which have
charge
Positively-charged ion /cation (loss e-)
Negatively charged ion / anion (gain e-)
+
-
8. Hydrogen atom Hydrogen ion
Magnesium atom
Oxygen atom
Chlorine atom Chlorine ion
H+
H
Lose electron
Lose electronMg
Magnesium ion
Mg2+
Oxide ion
O2
-
Gain electron
O
Cl
-
Gain electronCl
Particle theory
Symbol of element
Examples of ions:
10. The Historical Development Of
Atomic Models
• John Dalton – imagine atom as a
indivisible tiny ball
• J.J. Thomson – discovered electrons
• Ernest Rutherford – discovered proton,
mass of atom concentrated in nucleus
• Neils Bohr – proposed the electrons
move in shells around the nucleus
• James Chadwick – proved the existence
of neutrons
16. Subatomic Particle In An Atom
PROPERTIES PROTON NEUTRON ELECTRON
Symbol
Electric Charge
Relative Mass
Location
17. Subatomic Particle In An Atom
PROPERTIES PROTON NEUTRON ELECTRON
Symbol p
Electric Charge
Relative Mass
Location
18. Subatomic Particle In An Atom
PROPERTIES PROTON NEUTRON ELECTRON
Symbol p n
Electric Charge
Relative Mass
Location
19. Subatomic Particle In An Atom
PROPERTIES PROTON NEUTRON ELECTRON
Symbol p n e-
Electric Charge
Relative Mass
Location
20. Subatomic Particle In An Atom
PROPERTIES PROTON NEUTRON ELECTRON
Symbol p n e-
Electric Charge +1
Relative Mass
Location
21. Subatomic Particle In An Atom
PROPERTIES PROTON NEUTRON ELECTRON
Symbol p n e-
Electric Charge +1 0
Relative Mass
Location
22. Subatomic Particle In An Atom
PROPERTIES PROTON NEUTRON ELECTRON
Symbol p n e-
Electric Charge +1 0 -1
Relative Mass
Location
23. Subatomic Particle In An Atom
PROPERTIES PROTON NEUTRON ELECTRON
Symbol p n e-
Electric Charge +1 0 -1
Relative Mass 1
Location
24. Subatomic Particle In An Atom
PROPERTIES PROTON NEUTRON ELECTRON
Symbol p n e-
Electric Charge +1 0 -1
Relative Mass 1 1
Location
25. Subatomic Particle In An Atom
PROPERTIES PROTON NEUTRON ELECTRON
Symbol p n e-
Electric Charge +1 0 -1
Relative Mass 1 1 1/1240 ≈ 0
Location
26. Subatomic Particle In An Atom
PROPERTIES PROTON NEUTRON ELECTRON
Symbol p n e-
Electric Charge +1 0 -1
Relative Mass 1 1 1/1240 ≈ 0
Location in the
nucleus
atom
27. Subatomic Particle In An Atom
PROPERTIES PROTON NEUTRON ELECTRON
Symbol p n e-
Electric Charge +1 0 -1
Relative Mass 1 1 1/1240 ≈ 0
Location in the
nucleus
atom
in the
nucleus
atom
28. Subatomic Particle In An Atom
PROPERTIES PROTON NEUTRON ELECTRON
Symbol p n e-
Electric Charge +1 0 -1
Relative Mass 1 1 1/1240 ≈ 0
Location in the
nucleus
atom
in the
nucleus
atom
Electron
shells which
around the
nucleus atom
29.
30. 20
40
Ca
Nucleon number
Proton number
Symbol of Element
(1.refer ions)-When an atom is neutral ,
its number of proton = e-
- number of protons = 20
so number of elecrons = 20
- 2.electron configuration = 2.8.8.2
valence electron = 2
Symbol of element
3.Next
38. ARRANGEMENT OF SHELLS IN AN ATOM
NUCLEUS
2 ELECTRONS
8 ELECTRONS
8 ELECTRONS
18 ELECTRONS
1
2
3
4
39. Electron arrangement in the
carbon atom
C
12
6
proton number = 6
number of protons = 6
number of electrons = 6
2 . 4
= electron
nucleus
Number of valence
electrons = 4
40. 23
11
Na
2 . 8 . 1
number of protons = 11
proton number = 11
number of electrons = 11
= electron
Nucleus
Number of valence
electrons = 1 Symbol of element
41. Try to draw out
the electron
arran g emen t in
shells
42. Draw & state the electron arrangement of
the elements below
X
15
7
Y
24
12
Z
39
19
44. • Proton number (p) –
number of protons in the nucleus of atom
• Nucleon number (p+n)–
total number of protons and neutrons in
the nucleus of atom
3. Valence electron –
the electrons in the outermost shell
4. Electron configuration –
arrangement of electron
50. • Isotopes is just like twins,
same genetic but different of DNA
• atoms of the same element with
same number of protons but
different number of neutrons
What is isotopes?
51. Examples of Isotopes
• Take a look at Wikipedia isotopes table
• Hydrogen :
• Graphite :
• Oxygen :
1
H
1
3
H
1
2
H
1
12
C
6
14
C
6
13
C
6
16
O
8
18
O
8
17
O
8
53. Conclusion:
• Number of valence electron are same
• The chemical properties also same
• The physical properties might be
same, might be different
54. Elements Proton Number Nucleon Number
P 3 7
Q 9 19
R 16 32
S 15 31
T 16 33
U 18 40
Q3. Answer the structure questions
55. a ) What means proton number?
A: The numbers of proton in the nucleus of an atom
b)What means nucleon number?
A: The numbers of proton & neutron in the nucleus
of an atom
c) Write the electron arrangement for element Q.
A: 2.7
d)How many valence electrons that element Q has?
A: 7
e)How many electron shells that element Q has?
A: two
56. f) Which pair of elements are isotopes? Explain.
A: R & T.
Because they have same proton number but
different nucleon number
g) Is R&T have same chemical properties? Why?
A: Yes. BecauseUthey have same valence electron
• How many protons, neutrons, and electrons are
there in atom40
S?18
A: 15 protons, 16 neutrons and 15 electrons
i) Write the symbol to represent atom U.
A: 40
18
U