Imperial Physics v Imperial Chemistry v Cambridge NatSci

The two Part IA (second year) physics papers collectively more or less represent the entirety of year 2 (ish) physics teaching at more other unis. You usually don't get a great deal of choice in modules in physics degrees till third year anyway even at other unis, due to needing to cover a large chunk of core material regardless - usually where you do, it'll just be one or two and they'll really be more like "taster" modules in subfields of physics, because you won't have the breadth and depth in the core topics to really do anything more in depth. So the Cambridge format is not necessarily a bad thing.

Note though at Cambridge, usually you will end up specialising in one or the other by third year, and probably most often by second year for physics or chemistry - I gather you can go into Part II (third year) chemistry with only one of the options, but that it's unusual and your remaining options may be more restricted. For physics as noted since so much of the advanced physics optional content (at any uni) will depend on often quite a wide range of topics from the first two years, I'm not sure how likely it is to be able to go into that with just one of the two. So I expect in many case you'd really need to commit to either physics or chemistry by taking both options by second year.

As an aside, I think for physics and chemistry Cambridge normally have far more spaces for the MChem/MPhys year than students on the course, so the attrition factor is whether you meet the requirements to progress - which Imperial will also have (as normally if you average below a certain level, you will be required to switch to the BSc version of a course at most unis offering integrated masters courses). So I don't think this is as much a differentiating factor. They had on the natsci website somewhere the exact numbers for each course - as I recall basically all the fourth year courses in the physical sciences regime had more spaces than students normally on the third year course (I think the only ones where there were regularly far fewer spaces were HPS and systems biology, off hand?). Also you'll have pretty much the same kinds of research opportunities at Cambridge as at Imperial, so again, not really something that differentiates between the two.

I think really the major things you need to decide are:

a) Do you want to do physics, or chemistry? Invariably you have to make this decision sooner or later, and picking a course because it lets you defer that decision isn't really that great a reason to pick it in my opinion. I also don't really think it's that likely you will find your decision made in first year compared to now. So I think this is probably something you really need to think about now instead of trying to put off - even if you decide Cambridge is for you in the end! Your comment about practicals makes me think you are already leaning towards physics more, as chemistry is fundamentally a very practical oriented subject - although obviously physics is experimental as well so you will also have long practicals for physics, but they are usually not "wet" practicals like chemistry I gather so a bit different.

b) Do you want to study in London or not? You seem to really prefer the idea of living in London so that seems to incline you towards Imperial. Although it is worth noting if you just want to have access to London, Cambridge is very close - it's 45 minutes on the fast train, so easy to do a weekend day trip there or something. But it's not the same as living there to be fair! I'd note though the cost differential may not be as much - living in Cambridge is very expensive, even in college subsidised rooms. Also you will have shorter terms, which means less rent paid in Cambridge but more money spent going back and forth to home (with much of your stuff as well - since storage space out of term is, I gather, quite limited). Equally though, bear in mind in London you may well end up having to live much further out from Kensington in second year and onwards, and may spend half an hour or so commuting each day anyway depending exactly where you live and how much of the commute is tube vs walking!

@Sinnoh might be able to give some more insight into physics at Imperial if you have any specific queries which might help you confirm an interest (or not) in that option. @CheeseIsVeg may be able to offer some insight into chemistry at degree level in general if you have any specific queries about that too

thank you very much for the reply! I agree that I need to make a decision and I do think I'm leaning towards physics so I'm trying not to let the breadth of the cam course distract me. I enjoy chem and even if it's not really what I want to do anymore I'll be sad to give it up so another year would be nice
What you said about the masters made me feel much better. I scared myself because I found a document saying that to do part III chemistry you need to have averaged a 1st which seems a big gamble, but I've found out that physics only ask for a 2.1 which I think I could pull off (??)

About the research opportunities - Imperial heavily publicises their UROP scheme where undergrads are funded to assist with their lecturer's research over summer. This is a massive draw for me, I want to do research and also the idea of working on an actual research project as early as first year summer is amazing.
I haven't seen anything like that for Cambridge, they don't even mention research until 3rd year. On the other hand cam seems generally terrible at explaining how their courses work in any detail - I definitely get the vibe that once they give you an offer they expect you to firm, no questions asked, which is frustrating when unis like Imperial seem to be fighting for you to come. I know you said there's not much in the research opportunities, so have you heard of something similar at cam? I wouldn't put it past them to have the most amazing undergrad research scheme in the country and not mention it, I also wouldn't put it past them to keep undergrads as far away from their precious research as possible. (I've heard rumours that their weirdly short terms are to let the lecturers get on with research in the breaks without all those irritating students around...)

I do like the idea of living in London but the idea of having to find accommodation in second year and beyond is what puts me off. The idea of just going to cam and having it sorted is much less stressful.
Having run the numbers - London accommodation will definitely be more expensive than Cambridge, all rooms at my college cost the same at £185pw and I would get a long contract as I don't know whether I'll have a permanent bedroom at home by then because my mother is moving house. Due to a disability (which I don't get any funding for because I'm still on a diagnosis waiting list, fun times) I would really want to be near enough to the campus to come home easily which makes the cheapest room exactly £185, the same as Cambridge (and the chances of me getting that cheap room are pretty slim as they're obviously very high demand). Add to that cost of living stuff and how wildly that number will probably go up when I move to private renting and it doesn't look good!

I assure you that you could find summer research opportunities at Cambridge if you wished to. The research councils make regular funding for these programmes available at basically all unis to begin with, and Cambridge hosts a number of research institutes unto themselves which invariably will have some programmes.

Also summer research invariably involves doing grunt work for a researcher - they want undergrads to do this because they don't want to do it themselves...they just need the data for their next paper or whatever. Or they are actually really into teaching, although this is more variable This is especially true for doing research in the summer after your first year where you don't really have enough background to do anything but crunch data or something...

I'm pretty sure the terms are like that for reasons of "tradition" completely divorced with the structure of a modern day research university. There's probably a reason few other unis made since you know, the middle ages, have such a term structure. Also a longer term without supervisions is probably less total teaching time than a shorter term with supervisions.

In terms of the rental situation, I don't even think it's normally possible to get a "long contract" at Cambridge. Have you actually checked this for the colleges you are looking at? My understanding is that it's very rare to be able to stay in your rooms over the breaks at Cambridge and often you can only stay in your rooms for a maximum of so many days each year anyway beyond the normal contract (paying for each day...).

thank you very much for the reply! I agree that I need to make a decision and I do think I'm leaning towards physics so I'm trying not to let the breadth of the cam course distract me. I enjoy chem and even if it's not really what I want to do anymore I'll be sad to give it up so another year would be nice
What you said about the masters made me feel much better. I scared myself because I found a document saying that to do part III chemistry you need to have averaged a 1st which seems a big gamble, but I've found out that physics only ask for a 2.1 which I think I could pull off (??)

About the research opportunities - Imperial heavily publicises their UROP scheme where undergrads are funded to assist with their lecturer's research over summer. This is a massive draw for me, I want to do research and also the idea of working on an actual research project as early as first year summer is amazing.
I haven't seen anything like that for Cambridge, they don't even mention research until 3rd year. On the other hand cam seems generally terrible at explaining how their courses work in any detail - I definitely get the vibe that once they give you an offer they expect you to firm, no questions asked, which is frustrating when unis like Imperial seem to be fighting for you to come. I know you said there's not much in the research opportunities, so have you heard of something similar at cam? I wouldn't put it past them to have the most amazing undergrad research scheme in the country and not mention it, I also wouldn't put it past them to keep undergrads as far away from their precious research as possible. (I've heard rumours that their weirdly short terms are to let the lecturers get on with research in the breaks without all those irritating students around...)

I do like the idea of living in London but the idea of having to find accommodation in second year and beyond is what puts me off. The idea of just going to cam and having it sorted is much less stressful.
Having run the numbers - London accommodation will definitely be more expensive than Cambridge, all rooms at my college cost the same at £185pw and I would get a long contract as I don't know whether I'll have a permanent bedroom at home by then because my mother is moving house. Due to a disability (which I don't get any funding for because I'm still on a diagnosis waiting list, fun times) I would really want to be near enough to the campus to come home easily which makes the cheapest room exactly £185, the same as Cambridge (and the chances of me getting that cheap room are pretty slim as they're obviously very high demand). Add to that cost of living stuff and how wildly that number will probably go up when I move to private renting and it doesn't look good!