Trends in Properties of Elements in the Periodic Table

Classify elements as metals, metalloids and non-metals, explain how reactivity changes down groups and across periods, compare the chemical properties of metals and non-metals, and link each element's properties to its uses in Rwanda and beyond.

2

Chemical Bonding

Explain why atoms bond, describe ionic, covalent and metallic bonding with dot-and-cross diagrams, write formulae from ion charges and valencies, and use structure and bonding to explain melting points, conductivity and solubility.

3

Categories of Chemical Reactions

Write balanced equations and classify reactions as combination, decomposition, combustion, displacement or double decomposition, describe exothermic and endothermic changes using bond energies, and reduce reactions to ionic equations.

4

Inorganic Salts: Properties, Preparation and Identification of Ions

Name salts and write their formulae, explain solubility and saturation, choose the right method to prepare soluble and insoluble salts, relate salts to fertilisers, farming and daily life in Rwanda, and identify common cations and anions by laboratory tests.

5

The Mole Concept

Count particles with the mole, move between mass, moles, number of particles and gas volume, calculate percentage composition and empirical and molecular formulae, and use balanced equations to find reacting masses, limiting reactants and yields.

6

Preparation of Oxygen and Its Properties

Oxygen keeps you alive and makes fuels burn. You will prepare it safely in the laboratory, choose the right way to collect a gas, test for oxygen and describe its properties, and explain how it is used in medicine, industry and nature.

7

Preparation and Classification of Oxides

Oxides are everywhere, from sand and rust to the lime on a farmer's field. You will name and prepare oxides, classify them as acidic, basic, amphoteric or neutral by how they react, and explain how slaked lime is made and why oxides are so useful.

8

Electrolytes and Non-Electrolytes

Why does salty water conduct electricity while sugary water does not? You will explain conduction by mobile ions, distinguish strong, weak and non-electrolytes, and apply this to oral rehydration, batteries, electroplating and electrical safety.

9

Chemical Properties of Acids and Bases

Acids and bases are in your kitchen, your stomach and your school laboratory. You will prepare acids and bases, predict the products of their reactions with metals, metal oxides, carbonates and hydrogencarbonates, and use them safely, knowing both their uses and their dangers.

Units