What element has the symbol 'Pd'?

The story behind the answer

Pd is the symbol for Palladium. The similar-sounding elements use different symbols: Platinum is Pt (note the “t”), Phosphorus is P, and Polonium is Po (with an “o”).

Discovered by William Hyde Wollaston in 1803, palladium was named after the asteroid Pallas. It’s a rare, silvery metal in the platinum group and is prized for its ability to absorb hydrogen and catalyze reactions—key to cleaning car exhaust in catalytic converters. Memory tip: “Pd = PallaDium” (focus on the D), and “Palladium purifies pollution.” Meanwhile, “Platinum has a ‘t’ → Pt,” “Phosphorus is plain ‘P’,” and “Polonium has an ‘o’ → Po.”