| Answer | Crossword Clue |
|---|---|
| OXYGEN | Most abundant element in the earth's crust |
| SODIUM | Sixth most abundant element in the Earth's crust |
| SILICIC | Pertaining to the second most common element in the Earth's crust |
| ALUMINUM | Most abundant metal in earth's crust |
| ASTATINE | Rarest naturally occurring element in the earth's crust |
| silicon | nonmetallic element that constitutes more than one fourth of the earth's crust in its combined forms |
