Elements 55-86: period 6, with the lanthanides
32 elements, all in period 6. Ce to Lu sit in the f-block, which has no group number. Most tables put lanthanum (57) and actinium (89) in group 3, as ours does; some put lutetium (71) and lawrencium (103) there instead. IUPAC has not settled the question.
Row six holds gold, platinum, mercury and lead, and the fifteen lanthanides that are tucked below the main table. Every element in this list is in period 6.
This row is long (32 elements), so the chunks matter. Learn the two s-block metals, then the lanthanides in three chunks of five, then the transition metals, then the p-block. A story chain helps with the lanthanides: link each name to the next in one silly scene. Au (aurum), Hg (hydrargyros, liquid silver), Pb (plumbum) and W (wolfram) are the odd symbols to drill.
Encode make it vivid → Space bring it back on day 1, 3, 7, 21 → Retrieve pull it from your head. From the infographic Remember It on Purpose.
Elements 55-86: period 6, with the lanthanides
| Atomic number | Symbol | Element | Group |
|---|---|---|---|
| 55 | Cs | Cesium | 1 |
| 56 | Ba | Barium | 2 |
| 57 | La | Lanthanum | 3 |
| 58 | Ce | Cerium | f-block |
| 59 | Pr | Praseodymium | f-block |
| 60 | Nd | Neodymium | f-block |
| 61 | Pm | Promethium | f-block |
| 62 | Sm | Samarium | f-block |
| 63 | Eu | Europium | f-block |
| 64 | Gd | Gadolinium | f-block |
| 65 | Tb | Terbium | f-block |
| 66 | Dy | Dysprosium | f-block |
| 67 | Ho | Holmium | f-block |
| 68 | Er | Erbium | f-block |
| 69 | Tm | Thulium | f-block |
| 70 | Yb | Ytterbium | f-block |
| 71 | Lu | Lutetium | f-block |
| 72 | Hf | Hafnium | 4 |
| 73 | Ta | Tantalum | 5 |
| 74 | W | Tungsten | 6 |
| 75 | Re | Rhenium | 7 |
| 76 | Os | Osmium | 8 |
| 77 | Ir | Iridium | 9 |
| 78 | Pt | Platinum | 10 |
| 79 | Au | Gold | 11 |
| 80 | Hg | Mercury | 12 |
| 81 | Tl | Thallium | 13 |
| 82 | Pb | Lead | 14 |
| 83 | Bi | Bismuth | 15 |
| 84 | Po | Polonium | 16 |
| 85 | At | Astatine | 17 |
| 86 | Rn | Radon | 18 |
This row is long (32 elements), so the chunks matter. Learn the two s-block metals, then the lanthanides in three chunks of five, then the transition metals, then the p-block. A story chain helps with the lanthanides: link each name to the next in one silly scene. Au (aurum), Hg (hydrargyros, liquid silver), Pb (plumbum) and W (wolfram) are the odd symbols to drill. · teddyrookbook.com/memory/challenges/elements-55-86/
Sources
- Teddy Rook Book periodic table data (data/elements/elements.json; IUPAC/CIAAW and NIST)
- PubChem (NIH): Periodic Table of Elements, with standard state
- PubChem (NIH): IUPAC Periodic Table of the Elements and Isotopes
Checked October 30, 2026. Progress is kept on this device only (per learner). More lists: all memory challenges · memory games.