# Introduction and guidance

This free badged course, Discovering chemistry, is eight sessions in length with approximately three hours’ study time for each session.

Chemistry lies at the centre of our modern life, playing a part in areas as diverse as the development of new drugs and materials, analysing our environment through to more mundane activities such as washing your clothes and making your tea. But to truly understand the role chemistry plays you need to have a sound grasp of a number of fundamental principles.

This course introduces you to some of these concepts, beginning with the idea that everything that you can see is made of building blocks called atoms. This leads on to a look at the chemical elements and how they are arranged in the periodic table, enabling chemists to rationalise patterns in their chemical and physical behaviour.

Next you will consider chemical reactions, specifically how atoms combine with other atoms to form molecules, and how molecules combine with other atoms or molecules to form bigger molecules. You will meet simple (tried and tested) theories to explain the bonding in molecules and how their shapes may be explained, and indeed predicted. And in a wider sense you’ll be looking at why reactions happen at all and how fast they go.

This is also a beginner’s level course in the language of the chemist; you’ll learn about symbols, formulas and how chemical equations which represent reactions are constructed. Finally you will see how chemists count atoms and molecules, essential for making up solutions of a known concentration in order to carry out a reaction, or performing a chemical analysis.

After studying this course you should be able to:

- explain what is meant by isotopes, atomic numbers and mass numbers of the atoms of chemical elements
- indicate ways in which the chemical periodicity represented by the periodic table is reflected in the electronic structure of atoms
- explain how the molecular structure of chemical compounds is linked to their macroscopic properties
- understand ionic, covalent and metallic bonding
- construct balanced chemical equations for reactions
- use the Lewis structures of some simple chemical substances to illustrate the ideas of the octet rule, the electron-pair bond, and rationalise the three-dimensional structure of molecules
- select a set of organic molecules, each of which contains the same functional group, and use its reactions to show why the functional group concept is useful
- understand the use of the mole as a measure of the amount of a substance
- appreciate various facets of chemical reactions, why they occur and how fast they go, and the role of catalysts.

## Moving around the course

In the ‘Summary’ at the end of each session, you will find a link to the next session. If at any time you want to return to the start of the course, click on ‘Course content’. From here you can navigate to any part of the course. Alternatively, use the week links at the top of every page of the course.

It’s also good practice, if you access a link from within a course page (including links to quizzes), to open it in a new window or tab. That way you can easily return to where you’ve come from without having to use the back button in your browser. You can do this by holding down the ‘CTRL’ key (or CMD on a Mac) and left clicking the mouse button; or right click and ‘open link in new tab’.

OpenLearn - Discovering chemistry
Except for third party materials and otherwise, this content is made available under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 Licence, full copyright detail can be found in the acknowledgements section. Please see full copyright statement for details.