If you read the information about applying for Natural Sciences, you'll see that all applicants are required to take the Natural Sciences Admissions Assessment.
As well as the overview of the format, a list of assumed knowledge and example questions are available in the Natural Sciences Admissions Assessment Specification pdf linked under 'Admissions Assessment' on the Cambridge Admissions website. You'll find the example questions towards the end of the pdf.
It's worth bearing in mind that the Natural Sciences specification overlaps with the BMAT (taken by applicants for Medicine at Cambridge). The topics are even labelled using the same codes. A couple of additional notes may therefore be helpful for prospective Natural Sciences applicants:
- This BMAT Section 2 Guide can also be used to check that you know some of the more basic assumed knowledge for the Natural Sciences Admissions Assessment. The BMAT Section 2 Guide covers knowledge typically covered in non-specialist school Science and Mathematics subjects by the age of 16 (for example, GCSE in the UK and IGCSE internationally), though do bear in mind that it doesn't cover Advanced Maths and Advanced Physics.
- You might also find it helpful to have a go at the multiple choice sciences questions in past BMAT Section 2 papers. These are useful for getting used to the speed with which you need to get through material (and therefore the familiarity that you need with the assumed knowledge). These BMAT sections are only 30 minutes long, so they are good for giving you a quick go. For information, the difference between Natural Sciences Admissions Assessment questions and BMAT questions is that the BMAT questions are a little shorter in general (e.g. one fewer step/calculation) and all of Maths / Physics / Chemistry and Biology are contained (and alternate) through a single paper.
Back to the Natural Sciences page, resources section.