Elements are the pure substances and there are 118 elements in toto on earth. Lithium is the lightest element on earth with density of only 0.533 units. 94 elements are found naturally on earth and out of 118 about 80 elements are stable while elements with more than 83 or more atomic numbers are unstable. Here are the top ten lightest elements on earth with their discoverers and density.
| No. | Element | Discoverer Country | Discovered Year | Density |
| 1. |
Lithium |
J.A Arfvedson — Sweden
|
1817 | 0.533 |
| 2. |
Potassium |
Sir Humphry Davy – UK | 1807 | 0.859 |
| 3. |
Sodium |
Sir Humphry Davy | 1807 | 0.969 |
| 4. |
Calcium |
Sir Humphry Davy | 1808 | 1.526 |
| 5. |
Rubidium |
R.W. Bunsen/G. Kirchoff, Germany | 1861 | 1.534 |
| 6. |
Magnesium |
Sir Humphry Davy | 1808+ | 1.737 |
| 7. |
Phosphorus |
Hennig Brandt, Germany | 1669 | 1.825 |
| 8. |
Beryllium |
F. Wohler, Germany/ A.A.B. Bussy, France | 1828* | 1.846 |
| 9. |
Caesium |
R.W. Bunsen/G. Kirchoff | 1860 | 1.96 |
| 10. |
Sulphur |
Prehistoric | 2.070 |
Experiment is clear about Lithium being the most lightest element.