| Clue | Source | Date |
|---|---|---|
| The art student who was bored in chemistry class started to ... | Universal | 18 Sep 2025 |
| Cobalt and copper, in seawater | Newsday | 08 Aug 2020 |
| Outline hydrogen atoms? | ||
| Outline hydrogen atoms? | ||
| Selenium and zinc | ||
| Substances essential, in minute quantities, to nutrition |