How publishing works in this field
arXiv has been the field's de facto record since long before preprints spread elsewhere, and posting at submission is routine. Publishers in physics expect it and have no objection; the preprint is where priority is established and where most readers find the work.
Chemistry deposits as a condition of publication. Crystal structures go to the Cambridge Structural Database with a CCDC number, and NMR, mass spectrometry and elemental analysis data for new compounds are expected in the supporting information at a level that lets a referee check purity. Papers describing new compounds without that material are returned.
What slows papers down here
Authorship in large collaborations follows rules the collaboration sets rather than the journal, with alphabetical lists of hundreds and formal internal review before submission. Authors outside that system should not assume ordinary conventions apply, and assessment panels often misread these lists.
In chemistry, safety reporting is a live reviewer concern — hazardous procedures are expected to carry explicit warnings and handling details, and some journals require a dedicated safety statement.
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Questions we are asked in this field
Yes, across essentially all of physics and much of chemistry. It is the field's normal practice, establishes priority, and publishers expect it. Verify with an unfamiliar publisher, but this is settled territory.
Enough for a referee to judge identity and purity: NMR spectra, mass spectrometry, elemental analysis or equivalent, and for crystal structures a CCDC deposition number. Journals specify the exact set and will hold the paper without it.
Many physics journals prefer it and provide class files; most accept Word too. Where a journal supplies a template, use the current version — editorial offices return submissions built on outdated class files.