In the general case, when you're unsure whether a question belongs in one domain or another, just ask in chat on one of the sites, before posting your question. People there should be able to help you formulate your question, and guide you as to where it belongs.
In this specific case, it seems to me that the actual question you care about does belong on Health.SE. The question just needs some radical editing.
I think your underlying question is something like:
I notice that on food labels, instead of listing the amount of salt present, they list the amount of sodium. Is that because the health risk of too much or too little salt intake, derives entirely from the sodium? That is, is the chloride not really relevant to health, it's the sodium, and there are other sources of sodium in food in addition to salt? Why is "salt" referred to as "sodium" in nutrition facts (on food products) and similar documents?
As it happens, there are indeed linguistic and chemistry aspects to your question too, and a good answer should pick up on those as well as the health element.