1. Examination
 Paper 1 (50 marks)
 50 objective questions
 Paper 2 (100 marks)
 Section A, structure – 6 Questions (60 Marks)
 Section B, essay – 2 Questions, Choose only 1 question (20 Marks)
 Section C, essay– 2 Questions, Choose only 1 question (20 Marks)
 Paper 3 (50 Marks)- Experiment
 Question 1 – 33 marks (Structure)
 Question 2 – 17 marks (Report Experiment)

2. Experiment 1
 To determine the Melting and Freezing point of
Naphthalene/Acetamide.
Draw the procedure for this experiment in your exercise book
and bring it on:
 Date: Friday (11/1/13)
 Time: 2.45p.m.
 Venue: Chemistry Lab
 Wear shoes and proper school uniform
 Don’t bring any food, drink and school bag in the lab.

3. Report
Submit: Monday
 Name
 Class
 Aim
 Problem statement
 Hypothesis
 Variables (manipulated, responding, fixed)
 Apparatus
 Materials
 Procedure
 Result (In table & plot graph)
 Inference
 Calculation if necessary
 Discussion (Questions will be given)
 Conclusion

4. THE STRUCTURE OF
THE ATOM
Chapter 2

5. In this chapter, you will learn to:
Analyse matter
Synthesise the atomic structure
Understanding isotopes and their uses
Understanding the electronic structure of an atom
Appreciate the orderliness and uniqueness of the atomic
structure.

6. Assignment
Development of Atomic Models
Group 1: John Dalton’s Model – 4 members
Group 2: J.J. Thomson’s Model - 3 members
Group 3: Ernest Rutherford’s Model– 4 members
Group 4: Neils Bohr’s Model - 4 members
Group 5: James Chadwick’s Model– 4 members

7. Symbol of Elements
Elements Symbol
Hydrogen
Lithium
Sodium
Potassium
Beryllium
Magnesium
Calcium
Boron
Aluminium
Carbon

8. Continue…
Elements Symbol
Silicon
Nitrogen
Phosphorus
Oxygen
Sulphur
Fluorine
Chlorine
Helium
Neon
Argon

9. 2.2 Atomic Structure
An atom contains three types of subatomic particles:
Particles Symbol Relative Relative mass
charge
Proton p +1 1
Neutron n 0 1
Electron e -1 1/1840
The protons and neutrons are found in the nucleus, while the
electrons move around the nucleus in fixed orbits.
The nucleus is positively charged because of the presence of
protons, which are positively charged. The neutrons are
neutral.

11. Continue…
A neutral atom contains the same number of electrons as the
protons.
Example:
 An Aluminium atom contains 13 protons and 13 electrons.
The number of protons in the nucleus of an atom is called its
proton number (atomic number).
The total number of protons and neutrons in the nucleus is
the nucleon number (mass number).
Nucleon Number = Number of Proton + Number of Neutron

12. Exercises
1. An element P has a nucleon number of 31 and a proton
number of 15. Find the number of protons, electrons and
neutrons in the atom.

13. The atom of an element is written with its symbol, nucleon
number and proton numbers as follows:
Nucleon number a
Proton number
Example:
b Y Symbol
40
20 Ca
 This means that a calcium atom has 20 protons and
(40 – 20 ) = 20 Neutrons.