Note: these videos are a very brief overview of what you should know and may not entirely cover your syllabus. It is important that you check your syllabus document to ensure that all learning points are covered.
http://https://youtu.be/4764-9m5aE0
http://https://www.youtube.com/watch?v=2MwqBVOqxAg&t=205s
Mrs Tagore's Science Page 