Chemistry is typically an experimental science and relies primarily on practical work. It is important for students to learn the techniques of handling laboratory apparatus and to pay special attention to safety while working in the laboratory. Accidents happened even to German chemist, Robert Bunsen, while working in the laboratory. Robert Bunsen spent most of his time doing experiments in the laboratory and at the age of 25, he lost an eye in a laboratory explosion due to the lack of proper eye protection.

In this section, students examine the appropriate use of simple apparatus and chemicals, and experimental techniques. Students need to be aware of the importance of purity in the electronic, pharmaceutical, food and beverage industries, and should be allowed to try out different methods of purification and analysis in school science laboratories. Students should be able to appreciate the need for precision and accuracy in making readings and also value the need for safe handling and disposing of chemicals.

1. Experimental Chemistry

Differences between atoms give elements their different chemical properties. Atoms of one or more substances (reactants) undergo some ‘rearrangements’ during a chemical change (reaction). These rearrangements form new and different substances (products). After the chemical reaction, all the atoms of the reactants are still present in the products. Balanced chemical equations can be written because of the law of conservation of mass. These equations make it possible to predict the masses of reactants and products involved in chemical reactions.

The idea of atoms and chemical bonding being the most important fundamental concept in chemistry is introduced. The knowledge of atomic structure opens the door for students to understand the world of chemical reactions. Students are also introduced to the use of models and theories in the study of the structures of atoms, molecules and ions, and the bonding in elements and compounds. Calculations for chemical reactions involving chemical formulae, reacting masses and volumes, and concentrations introduce students to the fundamentals of stoichiometry.

The Particulate Nature of Matter

2. Kinetic Particle Theory

3. Atomic Structure

4. Chemical Bonding

5. Writing Chemical Equations

Chemists like Svante Arrhenius played an important role in providing a comprehensive understanding of what happens in chemical reactions. In 1887, the Swedish chemist Svante Arrhenius proposed the theory that acids, bases, and salts in water are composed of ions. He also proposed a simple yet beautiful model of neutralisation – the combination of hydrogen and hydroxyl ions to form water.

In this section, candidates examine the chemical characteristic properties of acids, bases and salts, and also their reactions with substances. Candidates should be able to value the knowledge of the hazardous nature of acids/alkalis and the safe handling, storing and disposing of chemicals.

Acids, Bases and Salts

6. Acid Bases

7. Salts

8. Mole concept

The development of the Periodic Table started in the 1800s as chemists began to recognise similarities in the properties of various elements and place them in families. The most famous and successful classification, widely accepted by chemists, was published in 1869 by Dmitri Mendeleev, a Russian chemist. His Periodic Table arranged the elements known at that time, in order of increasing atomic masses.

In this section, students examine the periodic trends and group properties of elements, the occurrence of metals and their properties, reactivity and uses. Students should be able to appreciate the development of the Periodic Table and hence to envisage that scientific knowledge changes and accumulates over time, and also the need for conserving some of the finite resources.

Periodicity

9. Periodic Table

10. Metals