| PROTACTINIUM | Radioactive metallic element of the actinide series occurring as a decay product of uranium; atomic no. 91 (12) |
| ASTATINE | Radioactive chemical element of the halogen series occurring as a decay product of uranium and thorium; atomic no. 85 (8) |
| PROMETHIUM | Radioactive metallic element of the lanthanide series artificially produced by the fission of uranium; atomic no: 61 (10) |
| ACTINIUM | Radioactive metallic element that glows blue in the dark; a decay product of uranium (8) |
| NEPTUNIUM | Radioactive metallic element of the actinide series produced by neutron bombardment of uranium in nuclear reactors (9) |
| FERMIUM | Radioactive metallic element of the actinide series, atomic no 100 (7) |
| AC | A radioactive element of the actinide series. |
| VANUATU | Lead and uranium atomic team use principally in remote islands |
| NEODYMIUM | A toxic silvery-white metallic element of the lanthanide series, occurring principally in monazite |
| BROMINE | Noxious red liquid element of the halogen series occurring in seawater, atomic no. 35 (7) |
| NEUTRON | Beta decay product, at times |
| THORIUM | Radioactive metal of the actinide series whose isotope 232 is used as a nuclear power source; atomic no. 90 (7) |
| URANIUM | One of the actinide series |
| EMERALD | Occurring as a result of processes that happened over hundreds of millions of years, a green variety of beryl that is the traditional birthstone for May (7) |
| TECHNETIUM | Radioactive metallic element of the transition series produced by deuteron bombardment of molybdenum (1O) |
| RADIUM | Radioactive metallic element of the alkaline earth series discovered by Marie and Pierre Curie in 1898 (6) |
| EXANTHEMA | Skin rash occurring as a symptom of a disease such as measles or rubella (9) |
| BORON | Hard metalloid element occurring as a dark brown amorphous powder and black crystals; atomic number 5 (5) |
| RUMBELOW | A meaningless word, occurring as a burden in old sea-songs (8) |
| FELDSPAR | A rock-forming mineral typically occurring as a colourless or pale-coloured crystal (8) |
