| Answer | Crossword Clue |
|---|---|
| IRIDIUM | One of the heaviest substance known. |
| OSMIC | Of the heaviest known substance. |
| MASON | One of the surveyors of a well-known line. |
| SOT | One known to hit the bottle |
| METAL | Lithium is the lightest one known |
| MOUNTMCKINLEY | Peak that's known as "The Great One" |
