| Answer | Crossword Clue |
|---|---|
| FLUORINE | Most reactive element |
| HYDROGEN | Most abundant element |
| IRON | Element in most meteorites |
| OXYGEN | Most abundant element in the earth's crust |
| NEON | Fifth-most abundant element in the universe |
| IRON | Most common element on Earth, by mass |
| SODIUM | Sixth most abundant element in the Earth's crust |
| SILICIC | Pertaining to the second most common element in the Earth's crust |
