I solved today’s Collidl in four moves. (Spoiler: ¹⁷²Ba + ²²²Rn + ³H ⇒ ₁₅₉³⁹⁶UPe + 𝑛⁰) and claim naming rights for Kitbashium (Ki) to replace the placeholder name Unpentenium.
⬛⬛🟩⬛⬛
⬛⬛🟩⬛⬛
⬛🟨⬛🟨⬛
🟩🟩🟩🟩🟩
Pro Tip: liquify your target Radon and add a little freshly ground chilli to the Barium beam!