the.com/protactinium

means A rare, dense, silvery-grey radioactive metallic element (atomic number 91), one of the actinides, found in trace amounts in uranium ores and notoriously toxic and scarce.

from From the Greek prōtos, "first," plus actinium — literally "before actinium," because the element sits one step earlier in the radioactive decay chain that produces actinium. It was originally dubbed "protoactinium" when isolated in the early 20th century, then trimmed to the smoother "protactinium." The actinium half traces back to Greek aktis, "ray" or "beam" — a fitting root for a family of elements that won't stop radiating.