Some stackexchange science proposals are getting closed soon. Often on those sites a discusson/conflict between experts/students/laymen arises, what type of questions are off-topic or drive away experts. But GOOD popular-science and textbook questions might attract a lot students in such broad fields, which after 2-4 years become researchers themselves and could then contribute more high-level Q&A's than users being already experts but asking very few questions. This is a known pattern on SE, you need user learning a branch and contributing at least >5 questions a day to keep a site and participation alive. It's not like Quora, where you can follow a topic and wait for interesting questions, also Quora isn't creating top-content like mathematica.se, physics.se, cstheory.se with a healty community. Those different systems have dis-/advantages
Recently this discussion arose on biology.se too. Looking at the voting scores of those meta Q&A's some SE regulars seem to understand that generating questions is crucial for a successful site and stay patient, while other and often SE newcomer seem to favor popular-science free sites. theophys.se was closed due to lack of questions/traffic (everything else was fine).
Chemistry is a very similar field of very experimental, broad nature, also much less popular science questions, less blogs on chemistry like in physics/biology. I simply want to make you aware of this problem. Don't set quality/"experts-only" over number of incoming questions. Asking some to laymen/undergraduate students interesting questions just to attract more users/students to this site, which in 2-4 years will be a important factor to maintain a site, might be crucial. Study courses are more and more diversified into mathematical physics, bioinformatics, biochemistry..... There ARE actually many graduate students who are in specific fields of the big branches biology, chemistry, physics near to a popular-science than expert-level despite being natural-scientists, but nonetheless interested in those fields.
The current area51 requirements don't guarantee that a site and all your effort you put into the site will be successful in the end.
And remember, while a site like physics.se has a lot laymen/popular science questions, by using SE's strong search and tagging options you can filter out a lot of stuff interesting to graduate students and experts. Building sustaining healty high-quality online communities happens within time-scales of years, not months.
PS: I have crossposted this question to chemistry, biology. I think there should be more crossposting of such meta-threads, as many user don't read meta.stackoverflow, area51discussion and new user/proposal start to make mistakes in scope, judgement and moderation that are already known problems on SE and where some experienced SE regulars might know a good solution/compromise.
Links of interest on this topic/problem
Why did Theoretical Physics fail?
Should we be concerned about the lack of quality answers?
Should we worry about the amount of non-expert content on the site?