Thermal equilibrium, and hence the physical structure of The ISM depends on the chemical composition of the gas, because Gas cooling dominates the line emission, which depends on Special chemistry is particularly important in the star Formation of regions, as chemical complexity may occur in those areas The result on terrestrial life, either directly, or, is a lot More likely, the emission of the molecule line indirectly, and therefore on Abundance: In other words, the physical structure of the ISM depends On the chemical composition of gas
