Approximate abundances by number, relative to hydrogen, of the most abundant elements in the Milky Way galaxy
| Element . | Abundance . | Element . | Abundance . |
|---|---|---|---|
| H | 1 | Si | 3.16 × 10−5 |
| He | 9.77 × 10−2 | Mg | 3.63 × 10−5 |
| O | 5.75 × 10−4 | Fe | 3.31 × 10−5 |
| C | 2.14 × 10−4 | S | 1 × 10−5 |
| N | 6.2 × 10−5 | Na, Ca | 2 × 10−6 |
| Element . | Abundance . | Element . | Abundance . |
|---|---|---|---|
| H | 1 | Si | 3.16 × 10−5 |
| He | 9.77 × 10−2 | Mg | 3.63 × 10−5 |
| O | 5.75 × 10−4 | Fe | 3.31 × 10−5 |
| C | 2.14 × 10−4 | S | 1 × 10−5 |
| N | 6.2 × 10−5 | Na, Ca | 2 × 10−6 |