This is the model as you need to know it at GCSE.

Your A Level studies will taken you into a deeper understanding of its structure and move you beyond your present understanding. You must be willing to open up your mind and see things in a different light for this to be a true learning experience.

Remember that we are dealing with models not absolute truth. Different models describe some aspects of reality better than others do and scientists often have several 'on the go' at a time. Look critically at the pictures that scientists have built up in their minds to explain natural phenomena such as atoms. Appreciate the beauty of a model - how it can be used to predict behaviour and also appreciate its limitations. As we search for 'truth' about the Universe we constantly revise and refine our ideas.

Try to build up a picture of how our present understanding developed. Imagine what it was like to be a researcher a century ago. Think of the models that famous scientists had learnt at your age and how they had to refine these ideas to gain a better grasp of 'the truth'.

The more you learn, the more you will realise how little is really known and how much there is still to strive for. The quest for knowledge is very much out there. We now realise that our understanding is more incomplete than they did a hundred years ago!

This gives you a taster of an area of science that is pushing back the frontiers of science. You will be looking at the work that was done in the 1960s and 1970s. This is well established now but there is still plenty of research into this area going on in Universities around the world.