The chemical symbol for sodium is:

**The reasoning** Sodium's chemical symbol is **Na** because it comes from its Latin name, *Natrium*. In chemistry, many elements use symbols derived from their Latin or Greek names rather than their English names. This is an international standard — whether you're in Lagos or London, sodium is always "Na" on the periodic table. You just need to memorize this one, but understanding *why* it's not "S" or "So" helps it stick. **Why the wrong options tempt you** - **S** is actually sulfur (another Latin-derived symbol from *Sulphur*) - **So** looks logical if you're guessing from "sodium," but two-letter symbols follow specific rules — the second letter is always lowercase, and "So" isn't assigned to any element - **Sd** might seem reasonable as an abbreviation, but it doesn't exist on the periodic table **Quick takeaway** Remember: **Na = Natrium = Sodium** — Latin roots explain seemingly strange symbols, and knowing common ones (like K for potassium = *Kalium*, Fe for iron = *Ferrum*) will save you marks across chemistry questions!