What element has the symbol 'Ra'?

The story behind the answer

Radium is the element with the symbol Ra (atomic number 88). It’s an alkaline earth metal in Group 2. The other options have different symbols: Rhenium is Re, Rhodium is Rh, and Rubidium is Rb—so only Radium matches Ra.

Discovered by Marie and Pierre Curie in 1898, radium is famously radioactive and was once used to make glow-in-the-dark paints; this history includes the tragic “Radium Girls,” which reshaped safety standards. A handy memory tip: Ra = radiates → Radium. Also remember the mismatches: Re (Rhenium), Rh (Rhodium), Rb (Rubidium).