Oxygen is a key component of the atmosphere and is critical for the support of life. Its reactivity makes it essential for respiration and combustion reactions - both of which release energy. Oxides are formed when oxygen combines with other elements. Much of Earth's crust (48.5% by mass)  is composed of oxygen in the form of oxides ...

When non-metal atoms bond to other non-metal atoms they share electrons to form covalent bonds.   1.46 Activity 2. Crossing and dotting  Students should: 1.46 understand how to use dot-and-cross diagrams to represent covalent bonds in molecules. Dot and cross diagrams are a useful way of representing how atoms share electro...

 1.23 Family resemblances Hydrogen is often listed above group 1 the Alkali metals. Although like group 1 atoms, hydrogen atoms have a single electron in their outer shell, Hydrogen is not a metal.  Students should: 1.23 understand why elements in the same group of the Periodic Table have similarchemical properties 1.24 und...

Electrolysis is often used to give metal objects a decorative coating. This is known as electroplating.

 1.55 Using electrolysis Electrolysis happens when an electric current is passed through an ionic compound which has been melted or dissolved.  Electrolysis has a wide range of uses including : electroplating, extraction of aluminium, production of chlorine and the purification of copper . This post helps you to unders...

Particle theory explains why the smell of cooking in the kitchen can quickly be smelt by people in other rooms.

 1.3 Activity 4. A particular problem  Students should: 1.3 understand how the results of experiments involving the dilution of coloured solutions and diffusion of gases can be explained. Particle theory states that all matter consists of many, very small particles which are constantly moving or in a continual state of motion. T...

A question of balance

 Many chemical reactions can be reversed.   When this happens we can describe a forward reaction and a back reaction. Sometimes the forward and back reaction take place at equal rates. When this happens an Equilibrium is established  Students should: 3.17 know that some reactions are reversible and this is indicated by the symbo...

The Bast furnace enables us to extract pure iron from iron oxide

Modern methods   Activity 1 : Phytomining and Bioleaching Watch the video carefully, stopping where necessary to answer the questions below: QuestionsAnswers  Explain the main difference between high grade ore and low grade ore.What is happening to the supply of high grade copper ore?Explain what is meant by bioleachin...

Universal indicator is useful for giving an estimated value for the pH of a substance

Background  This topic is mostly about equilibria so it is important for students to understand that concept first. Before tackling this topic make sure you : understand dynamic equilibriacan write and manipulate equilibrium expressions for a range of reactions.can estimate the pH value of a solution using universal indicator know th...

Ethanol is the alcohol in alcoholic drinks

 4.29. Handle with care The alcohols are another homologous series like the alkanes and the alkenes. Alcohols contain a functional group made up of an oxygen atom and a hydrogen atom.  Ethanol is one member of the alcohol series. This is the alcohol in alcoholic drinks. Alcohols are good at dissolving things and are therefo...