What element has the symbol 'Sb'?

The story behind the answer

Antimony’s symbol is Sb because it comes from its Latin name, stibium. That’s why the more “obvious” letters (A or An) aren’t used. By contrast, Ag is silver (argentum), Na is sodium (natrium), and Sr is strontium—so Sb uniquely points to antimony.

Antimony is a metalloid near arsenic, used in flame retardants, alloys (to harden lead), and historically in kohl eyeliner. Memory tip: “Sb = StiBium = anti-mony” (think “anti-money” makeup from ancient times). If you remember that many symbols come from Latin, Sb→stibium→antimony will stick.