# Introduction

At the heart of chemistry is the chemical reaction, the transformation of one type of matter into another – a chemical change.

The ancient alchemists were obsessed with the transformation of base metals into gold, and the synthesis of an elixir of immortality. Today chemists carry out reactions, less rooted in the realms of fantasy to produce useful substances such as new drugs, electronic materials and fabrics.

So far in this course you have seen a number of examples of how chemists convert one substance to another.

In this session you will be looking at several facets of reactions and reactivity, and meet another example of the chemist’s language, the chemical equation. Finally, building on what you already know about molecular structure you will look at how reactivity is focussed at particular parts of molecules.

To set this topic in context a running theme will be the chemistry of what you might consider to be the archetypal reactive chemicals – explosives.

OpenLearn - Discovering chemistry
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