This document discusses particle theory and the structure of atoms. It begins by defining particles as the tiny discrete units that make up matter, including atoms, molecules, ions. It then discusses the historical development of atomic models from Dalton to Chadwick. Key points include: atoms consist of protons, neutrons, and electrons; protons have a positive charge, neutrons have no charge, and electrons have a negative charge. Electron configuration and the filling of electron shells in the first 20 elements is also explained. Isotopes are defined as atoms of the same element with different numbers of neutrons.

1. A MotivationalLesson
by
Dr. WaqarAhmad
Pharm-D(GoldMedalist)
M.PhilPharmacy(QAUIslamabad)

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:

9. 2.2 ATOMIC STRUCTURE

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

11. Subatomic Particle In An Atom

12. Subatomic Particle In An Atom
Proton
Neutron
Electron

13. Subatomic Particle In An Atom
Proton Electron
Neutron
Nucleus
of atom Electron
shells

14. Subatomic Particle In An Atom

15. Subatomic Particle In An Atom

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

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

31. Electron Configuration
Also known as electron arrangement
How electrons fill into the shells?

32. Helium He
Proton number 2
2
Hydrogen H
Proton number 1
1
Lithium
Proton number
Li
3
2 . 1
Beryllium
Proton number
Be
4
2 . 2

33. Boron B
proton number 5
2 . 3
Carbon
Proton number
C
6
2 . 4
Nitrogen
Proton number
N
7
2 . 5
Oxygen
Proton number
O
8
2 . 6

34. Fluorine
Proton number
F
9
2 . 7
Neon
Proton number
Ne
10
2 . 8
Sodium
Proton number
Na
11
2 . 8 . 1
Magnesium
Proton number
Mg
12
2 . 8 . 2

35. Aluminium
Proton number
Al
13
2 . 8 . 3
Silicon
Proton number
Si
14
2 . 8 . 4
Phosphorus
Proton number
P
15
2 . 8 . 5
Sulphur
Proton number
S
16
2 . 8 . 6

36. Chlorine
Proton number
Cl
17
2 . 8 . 7
Argon Ar
Proton number 18
2 . 8 . 8
Potassium K
Proton number 19
2 . 8 . 8 . 1
Calcium Ca
Proton number 20
2 . 8 . 8 . 2

37. Conclusion:
1st Shell: max 2 e-
2nd Shell: max 8 e-
3rd Shell: max 8 e-

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

43. Let us learn
some
chemical words !!

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

45. Elements Proton
Number
Nucleon
Number
Number
of
Neutrons
A 3 7
B 6 12
C 19 10
D 16 16
E 17 18
F 40 20
Q1 Fill in the blanks

46. Elements Proton
Number
Nucleon
Number
Number
of
Neutrons
A 3 7 4
B 6 12 6
C 9 19 10
D 16 32 16
E 17 35 18
F 20 40 20
Q1 Answers

47. Elements Number
of
Neutron
Nucleon
Number
Number
of
electrons
Electron
Configuration
A 5 9
B 8 2.6
C 19 2.7
D 14 2.8.3
E 32 16
F 20 40
Q2 Fill in the blanks

48. Elements Number
of
Neutron
Nucleon
Number
Number
of
electrons
Electron
Configuration
A 5 9 4 2.2
B 8 16 8 2.6
C 10 19 9 2.7
D 14 27 13 2.8.3
E 16 32 16 2.8.6
F 20 40 20 2.8.8.2
Q2 Answers

49. 2.3 ISOTOPES

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

52. Isotopes of Hydrogen
Hydrogen :
1
1
H
2
1
H
3
1
H

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