Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Clouds, Clumps, Cores & Comets - a Cosmic Chemical Connection?   We discuss the connection between the chemistry of dense interstellar clouds
and those characteristics of cometary matter that could be remnants of it. The
chemical evolution observed to occur in molecular clouds is summarized and a
model for dense core collapse that can plausibly account for the isotopic
fractionation of hydrogen, nitrogen, oxygen and carbon measured in primitive
solar system materials is presented.

17
The categories of this paper are: q-fin
12
The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol
20
The categories of this paper are: acc-phys
33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
16
The categories of this paper are: stat
24
The categories of this paper are: dg-ga
10
The categories of this paper are: q-bio
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th