The document discusses the structure of atoms and isotopes. It begins by defining matter and the particle theory of matter. It then explains that atoms are made up of protons, neutrons and electrons. The atomic structure of various elements is discussed through their electron configurations. Isotopes are then introduced as atoms of the same element that have the same number of protons but different numbers of neutrons. Examples of isotopes including hydrogen and oxygen isotopes are provided.

1. CHAPTER 2 THE STRUCTURE OF THE ATOM

2. 2.1 MATTER Most of the things that we could see in this world are MATTER

3. What is matter? Matter means: - anything that occupies space & has mass made up of tiny & discrete particles Exist as element @ compound Next

4. A pure substance which cannot be broken down into simpler substance physically & chemically Element Matter

5. Usually made up of two or more elements which are chemically bonded together Compound Matter

6. Matter are made up of tiny & discrete particles Size of particles are very minute ~~ 1x 10 -7 cm 3. Consist of atoms , molecules ions Particles Theory Next

7. Let’s see the particles in bromine liquid Particle theory

8. The smallest particle of an element and not breakable anymore. 1. A t o m s Examples: Atom of hydrogen atom of magnesium atom of oxygen atom of chlorine H Mg Cl O Particle theory

9. A group of two @ more atoms, which might consist of: one type of element (Element) @ different types of element (Compound) 2. M o l e c u l e s

10. Examples of element molecules: Molecule of hydrogen gas Molecule of oxygen gas Molecule of chlorine gas O O Cl Cl H H

11. Examples of compound molecules: Molecule of water , H 2 O Molecule of ammonia , NH 3 Molecule of ethanol , C 2 H 5 OH Particle theory H H O H H H N O C C H H H H H H

12. Ions are atoms which have charge Positively-charged ion / cation (loss e - ) Negatively charged ion / anion (gain e-) 3. I o n s + -

13. Examples of ions: Hydrogen atom Hydrogen ion Magnesium atom Magnesium ion Oxygen atom Ox ide ion Chlorine atom Chlorine ion Particle theory Symbol of element H + H Lose electron Mg 2+ Lose electron Mg O 2- Gain electron O Cl - Gain electron Cl

15. Kinetic means motion (move) Kinetic theory states that: 1. Matter consist of particles which constantly moving Kinetic theory

16. 2. particles move in random motion , collide with each other

17. substance is cooled , - particles lose kinetic energy - move slower B. substance is heated , - particles gain kinetic energy - move faster

18. Heat energy makes particles move faster!!!

19. Experiment which supports the kinetic theory: Investigating the diffusion of particles in a solid, liquid and gas

20. What is diffusion ? How diffusion supports the kinetic theory ?

21. Diffusion happens anyway that different concentration of particles

22. Is the rate of diffusion different in solid, liquid, and gas state? Let’s get an experiment to check it out!!!

23. Diffusion in Solid (membrane)

24. Diffusion in Liquid ( )

25. Diffusion in Gas (air)

26. Diffusion affected by Density

29. The conclusion is……. Diffusion happens in solid, liquid, and gas states Diffusion occurs slowest in solid, faster in liquid and fastest in gas Diffusion occurs faster in subtance with lower density Diffusion supports kinetic energy

31. The Physical States of Matter Solid Liquid Gas

32. The Arrangement of Particles

33. The Shape & Volume of Particles

34. The Movement & Energy Content of Particles

35. The Attraction Force between Particles

36. The Physical Changes of Matter Freezing Melting Sublimation Boiling Condensation Sublimation Gas Liquid Solid

37. Melting point – the temperature which a solid becomes liquid Determine the Melting Point of Naphthalene

38. Diagram of heating naphthalene Q1-Q4 Q5-Q7 Solid naphthalene Water

39. Heating curve of naphthalene Q1-Q4 Q5-Q7 A C B D Temperature / ˚C Time / minute 79˚C

41. What is the Melting point? A: 79˚C What is the physical state at B-C? A: solid and liquid Where is point that Melting process started? A: B Where is point that Melting process ended? A: C graph apparatus

42. Why the curve of heating has no change at B-C? A: because the heat energy absorbed by naphthalene molecules to overcome the forces of attraction to becomes liquid Why solid naphthalene heated in water ? A: to ensure a uniform heating If the melting point of Substance X is 123˚C, can we still use water as medium? Why? A: No. Because its melting point is higher than the boiling point of water. We can use oil bath to replace water. graph apparatus Physical changes

43. Freezing point – the temperature which a solution becomes solid Determine the Freezing Point of Naphthalene

44. Cooling curve of naphthalene Q1-Q4 Q5-Q7 79˚C E F Temperature / ˚C G H Time / minute

45. Is the freezing point same with the Melting point? A: Yes, both are 79˚C What is the physical state change in this experiment? A: Liquid naphthalene changes to solid Where is the point that freezing process started? A: F Where is the point that freezing process ended? A: G

46. Why the curve of heating has no change at F-G? A: because the heat energy released during formation of bonds is equal to the heat released to surroundings Why liquid naphthalene in the boiling tube is cooled inside a conical flask? A: to ensure a uniform cooling

47. Different solution has different boiling point & freezing point

48. Diagram of cooling naphthalene Q1-Q4 Q5-Q7 Liquid naphthalene Empty conical flask

49. 2.2 ATOMIC STRUCTURE

50. 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

51. Subatomic Particle In An Atom

52. Subatomic Particle In An Atom Proton Neutron Electron

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

54. Subatomic Particle In An Atom

55. Subatomic Particle In An Atom

56. Subatomic Particle In An Atom PROPERTIES PROTON NEUTRON ELECTRON Symbol Electric Charge Relative Mass Location

57. Subatomic Particle In An Atom PROPERTIES PROTON NEUTRON ELECTRON Symbol p Electric Charge Relative Mass Location

58. Subatomic Particle In An Atom PROPERTIES PROTON NEUTRON ELECTRON Symbol p n Electric Charge Relative Mass Location

59. Subatomic Particle In An Atom PROPERTIES PROTON NEUTRON ELECTRON Symbol p n e - Electric Charge Relative Mass Location

60. Subatomic Particle In An Atom PROPERTIES PROTON NEUTRON ELECTRON Symbol p n e - Electric Charge +1 Relative Mass Location

61. Subatomic Particle In An Atom PROPERTIES PROTON NEUTRON ELECTRON Symbol p n e - Electric Charge +1 0 Relative Mass Location

62. Subatomic Particle In An Atom PROPERTIES PROTON NEUTRON ELECTRON Symbol p n e - Electric Charge +1 0 -1 Relative Mass Location

63. Subatomic Particle In An Atom PROPERTIES PROTON NEUTRON ELECTRON Symbol p n e - Electric Charge +1 0 -1 Relative Mass 1 Location

64. Subatomic Particle In An Atom PROPERTIES PROTON NEUTRON ELECTRON Symbol p n e - Electric Charge +1 0 -1 Relative Mass 1 1 Location

65. 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

66. 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

67. 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

68. 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

69. Still awake ??

70. Symbol of Element When an atom is neutral , ( 1. refer ions) its number of proton = e - number of protons = 20 so number of elecrons = 20 - 2. electron configuration = 2.8.8.2 valence electron = 2 Nucleon number Proton number Symbol of element 3. Next 40 20 Ca

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

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

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

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

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

76. Chlorine Cl Proton number 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

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

78. ARRANGEMENT OF SHELLS IN AN ATOM NUCLEUS 2 ELECTRONS 8 ELECTRONS 8 ELECTRONS 18 ELECTRONS 1 2 3 4

79. 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

80. 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

82. Try to draw out the electron arrangement in shells

83. X Draw & state the electron arrangement of the elements below 15 7 Y 24 12 Z 39 19

84. Let us learn some chemical words !!

85. 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 outer most shell 4. Electron configuration – arrangement of electron

86. Repeat them !! Proton number number of protons in the nucleus of atom Nucleon number total number of protons and nucleons in the nucleus of atom Valence electron the electrons in the outermost shell Electron configuration – arrangement of electron

87. Try this out!!!

88. Q1 Fill in the blanks 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

89. Q1 Answers 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

90. Q2 Fill in the blanks 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

91. Q2 Answers 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

92. 2.3 ISOTOPES

93. 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?

94. Examples of Isotopes Take a look at Wikipedia isotopes table Hydrogen : Graphite : Oxygen : 1 1 H 3 1 H 2 1 H 12 6 C 14 6 C 13 6 C 16 8 O 18 8 O 17 8 O

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

96. Properties of isotopes Oxygen Isotopes No of proton No of neutron No of e - e - configuration Valence e - 16 8 O 18 8 O 17 8 O

97. Properties of isotopes Oxygen Isotopes No of proton 8 No of neutron No of e - e - configuration Valence e - 16 8 O 18 8 O 17 8 O

98. Properties of isotopes Oxygen Isotopes No of proton 8 8 No of neutron No of e - e - configuration Valence e - 16 8 O 18 8 O 17 8 O

99. Properties of isotopes Oxygen Isotopes No of proton 8 8 8 No of neutron No of e - e - configuration Valence e - 16 8 O 18 8 O 17 8 O

100. Properties of isotopes Oxygen Isotopes No of proton 16 16 16 No of neutron 16 No of e - e - configuration Valence e - 16 8 O 18 8 O 17 8 O

101. Properties of isotopes Oxygen Isotopes No of proton 16 16 16 No of neutron 16 17 No of e - e - configuration Valence e - 16 8 O 18 8 O 17 8 O

102. Properties of isotopes Oxygen Isotopes No of proton 16 16 16 No of neutron 16 17 18 No of e - e - configuration Valence e - 16 8 O 18 8 O 17 8 O

103. Properties of isotopes Oxygen Isotopes No of proton 16 16 16 No of neutron 16 17 18 No of e - 16 e - configuration Valence e - 16 8 O 18 8 O 17 8 O

104. Properties of isotopes Oxygen Isotopes No of proton 16 16 16 No of neutron 16 17 18 No of e - 16 16 e - configuration Valence e - 16 8 O 18 8 O 17 8 O

105. Properties of isotopes Oxygen Isotopes No of proton 16 16 16 No of neutron 16 17 18 No of e - 16 16 16 e - configuration Valence e - 16 8 O 18 8 O 17 8 O

106. Properties of isotopes Oxygen Isotopes No of proton 16 16 16 No of neutron 16 17 18 No of e - 16 16 16 e - configuration 2.8.6 Valence e - 16 8 O 18 8 O 17 8 O

107. Properties of isotopes Oxygen Isotopes No of proton 16 16 16 No of neutron 16 17 18 No of e - 16 16 16 e - configuration 2.8.6 2.8.6 Valence e - 16 8 O 18 8 O 17 8 O

108. Properties of isotopes Oxygen Isotopes No of proton 16 16 16 No of neutron 16 17 18 No of e - 16 16 16 e - configuration 2.8.6 2.8.6 2.8.6 Valence e - 16 8 O 18 8 O 17 8 O

109. Properties of isotopes Oxygen Isotopes No of proton 16 16 16 No of neutron 16 17 18 No of e - 16 16 16 e - configuration 2.8.6 2.8.6 2.8.6 Valence e - 6 16 8 O 18 8 O 17 8 O

110. Properties of isotopes Oxygen Isotopes No of proton 16 16 16 No of neutron 16 17 18 No of e - 16 16 16 e - configuration 2.8.6 2.8.6 2.8.6 Valence e - 6 6 16 8 O 18 8 O 17 8 O

111. Properties of isotopes Oxygen Isotopes No of proton 16 16 16 No of neutron 16 17 18 No of e - 16 16 16 e - configuration 2.8.6 2.8.6 2.8.6 Valence e - 6 6 6 16 8 O 18 8 O 17 8 O

112. Conclusion: Number of valence electron are same The chemical properties also same The physical properties might be same, might be different

113. Try this out!!!

114. Q3. Answer the structure questions Elements Proton Number Nucleon Number P 3 7 Q 9 19 R 16 32 S 15 31 T 16 33 U 18 40

115. 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

116. 40 18 U 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. Because they have same valence electron How many protons, neutrons, and electrons are there in atom S? A: 15 protons, 16 neutrons and 15 electrons i) Write the symbol to represent atom U. A: 40 18 U