Many questions on Chemistry.SE will have to do with certain elements or molecules. In these situations, should the question be tagged with those names?
My feeling is that in most cases, they will add little or nothing to the question, and should be avoided. I would be for tags like halogens that cover a number of elements, as those would much fewer in number, and would be used less often.
As a rule, I would suggest that groups of things are OK (eg aromatic-compounds) but not single items.
I'm against it. Tags are so that specialists/etc can find stuff. I've never heard of a specialist in an element.
All it would do would be to make it easier to search for those elements. And not too easier, typing "tungsten" in the search box should be good enough.
Tagging according to categories/groups is fine, IMO (rare earth/alkali/alkaline earth/halogen/etc). But we should only tag if the question pertains to the property of that group/properties of a particular element in that group. Don't go tag-crazy on questions where an element is mentioned.
Always keep in mind that the tags are for filtering out questions.
If the question is about a specific element, e.g. Silver, its bactericidal features and water (not the best question), I'm neutral on the issue, and perhaps lean ever so slightly towards keeping them.
There are fields of chemistry that are focused on particular elements though; fluorine chemistry seems to be all the rage nowadays. I would encourage some tag like fluorine-compounds, fluorine-chemistry, or maybe simply fluorine (though the last one might encourage people to overuse it).
On the other end, questions about organic compounds should not be tagged hydrogen carbon... If we tried to do biological molecules you'd just hit the tag limit (carbon hydrogen nitrogen oxygen sulfur)