  Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus and Sulfur (CHNOPS) play key
roles in the origin and proliferation of life on Earth. Given the universality
of physics and chemistry, not least the ubiquity of water as a solvent and
carbon as a backbone of complex molecules, CHNOPS are likely crucial to most
habitable worlds. To help guide and inform the search for potentially habitable
and ultimately inhabited environments, we begin by summarizing the CHNOPS
budget of various reservoirs on Earth, their role in shaping our biosphere, and
their origins in the Solar Nebula. We then synthesize our current understanding
of how these elements behave and are distributed in diverse astrophysical
settings, tracing their journeys from synthesis in dying stars to molecular
clouds, protoplanetary settings, and ultimately temperate rocky planets around
main sequence stars. We end by identifying key branching points during this
journey, highlighting instances where a forming planets' distribution of CHNOPS
can be altered dramatically, and speculating about the consequences for the
chemical habitability of these worlds.
