Timeline of chemical element discoveries Modern discoveries Modern discoveries

| Z | Element_ | Observed_or_predicted | Isolated_widely_known | Observer | First_isolator | Notes_ |
|---|---|---|---|---|---|---|
|  |  | 1789 |  | A. Lavoisier |  | The first modern list of chemical elements – containing, among others, 23 elements of those known then. He also redefined the term element. Until then, no metals except mercury were considered elements. |
| 40 | Zirconium | 1789 | 1824 | H. Klaproth | J. Berzelius | Klaproth identified a new element in zirconia. |
| 92 | Uranium | 1789 | 1841 | H. Klaproth | E.-M. Péligot | Mistakenly identified a uranium oxide obtained from pitchblende as the element itself and named it after the recently discovered planet Uranus. |
| 22 | Titanium | 1791 | 1825 | W. Gregor | J. Berzelius | Gregor found an oxide of a new metal in ilmenite; Martin Heinrich Klaproth independently discovered the element in rutile in 1795 and named it. The pure metallic form was only obtained in 1910 by Matthew A. Hunter. |