| LOCKYER | Norman -, astronomer jointly credited with detecting the element helium (7) |
| RHENIUM | Element helium with nickel in strange surroundings (7) |
| RAREGAS | Any of the unreactive elements helium, neon, argon, krypton, radon and xenon (4,3) |
| MERCURY | Named after a talaria-wearing swift-flying Roman messenger god, the first planet from the Sun or, the element with the symbol Hg (7) |
| HE | Symbol for the element helium (2) |
| ARSENIC | Featuring in the title of a play adapted into a film by Frank Capra, the element with germanium to its left and selenium to its right on the periodic table (7) |
| IRIDIUM | The element was discovered in 1803 in the acid-insoluble residues of platinum ores by the English chemist Smithson Tennant. The international prototype standard kilogram of mass is made from an alloy |
| ABELSON | Philip ___, co-discoverer with Edwin McMillan of the element neptunium (7) |
| NIOBATE | A salt containing the element with atomic number 41 (7) |
| OXIDISE | Combine chemically with the element of atomic number 8 (7) |
| LITHIUM | The element of humility endlessly exercised (7) |
| CAESIUM | Sauce I'm spreading on the element (7) |
| WOLFRAM | Former name of the element tungsten (7) |
| CROOKES | William ___, English chemist and physicist who discovered the element thallium in 1861 (7) |
| STIBIUM | Word from which the element antimony derives its symbol (7) |
| LEIBNITZ | Wilhelm ____ is jointly credited for the discovery of calculus |
| IRONORE | Rocks and minerals from which the element with atomic number 26 can be extracted (4,3) |
| HALOGEN | The element that may hang Leo |
| OXYACID | Corrosive substance containing the element O |
| TINWORK | Craft using the element Sn |
