Undergraduate courses in chemistry are taught under the umbrella of the Natural Sciences Tripos. Within this, Chemistry is an option in all four years.
If you are not familiar with the Cambridge system you might find it helpful to look at the frequently asked questions.
In the first year (Part IA), Natural Science students (always called NatScis) can take Chemistry as one of their three experimental sciences. Details of the course can be seen by following the course guide on the left.
In the second year (Part IB) two Chemistry courses are on offer. Chemistry A covers mainly Physical and Theoretical Chemistry, while Chemistry B covers mainly Organic and Inorganic Chemistry. Those intending to specialise in Chemistry usually take both of these courses, but this is not a requirement for proceeding to the third year. Often, NatScis heading for other specialisms take just one of these two. The course guide link opposite gives more details about the Second Year courses.
In the Third and Fourth years you can specialise completely in Chemistry. You can either choose to graduate after three years (with the BA) having completed Part II or alternatively you can take Part II and then carry on for the fourth year to complete Part III. At the end of the fourth year you graduate with an MSci (which is equivalent to an MChem) and are also awarded a BA. More details can be found in the course guides link below.
For full details of the courses please follow the Course Guides link