Chemical elements that have been mistakenly "discovered". Further investigation showed that their discovery was either mistaken, that they have been mistaken from an already-known element, or mixture of two elements, or that they indicated a failing in theory where a new element had been assumed rather than some previously unknown behaviour.
| Name | Symbol | Atomic number | Actual element | Discovery date | Discoverer | |||
|---|---|---|---|---|---|---|---|---|
| Ab | 85 | 1931 | data-sort-value="Allison, Fred" | Fred Allison | ||||
| 87 | 1926 | data-sort-value="Druce, Gerald J. F." | Gerald J. F. Druce, Frederick H. Loring | |||||
| See Helvetium | ||||||||
| 1911 | data-sort-value="Nicholson, J. W." | J. W. Nicholson | ||||||
| 1898 | data-sort-value="Lockyer, Norman" | |||||||
| 1874 | data-sort-value="Huggins, William" | [1] | ||||||
| Ao | 93 | 1934 | data-sort-value="Fermi, Enrico" | |||||
| 31 | 1886 | data-sort-value="Linnemann, Eduard" | Hypothesised from spectral line observations in the rare-earth mineral orthite.[2] It was later confirmed that these lines were due to the recently discovered gallium. | |||||
| Bz | 90 | 1901 | data-sort-value="Baskerville, Charles" | Charles Baskerville | See Carolinium | |||
| 93 | 1934 | data-sort-value="Koblic, Odolen" | ||||||
| Cn | 90 | 1901 | data-sort-value="Baskerville, Charles" | With Berzelium, erroneously identified as a mixture of three elements, with thorium, during work at the University of North Carolina.[3] | ||||
| 26 | 1869 | data-sort-value="Young, Charles Augustus" | Hypothesised from a 530.3 nm green emission line in the solar coronal spectrum. Later, around 1902, renamed as Newtonium. In the 1930s recognised as highly ionized iron, rather than a new element. | |||||
| 61 | 1941 | data-sort-value="Prout, William" | ||||||
| Dk | 85 | 1937 | data-sort-value="De Cepare, Rajendralal" | Rajendralal De Cepare | ||||
| 1877 | data-sort-value="Kern, Serge" | [4] | ||||||
| 1878 | data-sort-value="Delafontaine, Marc" | Thought to have been isolated from the mineral samarskite in 1878.[5] | ||||||
| 1860 | data-sort-value="Kobell, von, Wolfgang Franz" | See Pelopium | ||||||
| 1841 | data-sort-value="Mosander, Carl" | |||||||
| 85 | 1936 | data-sort-value="Hulubei, Horia" | ||||||
| 87 | ||||||||
| 107 | ||||||||
| 61 | 1924 | data-sort-value="Rolla, Luigi" | Luigi Rolla and Lorenzo Fernandes | |||||
| Gh | 118 | 1999 | data-sort-value="Lawrence Berkeley National Laboratory" | |||||
| 1892 | data-sort-value="" | Not discovered, but hypothesised to explain discrepancies within the iron group elements for an early periodic table ordered by mass. The concept of atomic number clarified the situation without requiring the invention of a new element. | ||||||
| 85 | 1940 | data-sort-value="Minder, Walter" | Rediscovered in 1942 and named Anglohelvetium | |||||
| Hs | 94 | 1934 | data-sort-value="Fermi, Enrico" | |||||
| 61 | 1926 | data-sort-value="Hopkins, Smith" | ||||||
| 1847 | data-sort-value="Hermann, R" | R. Hermann | See Pelopium | |||||
| 39 | 1896 | data-sort-value="Barrière, Prosper" | ||||||
| 43 | 1925 | data-sort-value="Noddack, Walter" | ||||||
| Mi | 87 | 1936 | data-sort-value="Hulubei, Horia" | |||||
| 1898 | See Victorium | |||||||
| 17 | 1774 | data-sort-value="Scheele, Carl Wilhelm" | ||||||
| 1785 | data-sort-value="Berthollet, Claude Louis" | |||||||
| 1864 | data-sort-value="Huggins, William" | |||||||
| 0 | (Neutronium) | 1926 | data-sort-value="Antropoff, Andreas" | |||||
| 1902 | See Coronium | |||||||
| Nv | 118 | 1999 | data-sort-value="Ninov, Victor | Victor Ninov | Studies proved inconsistencies in the data shown from Victor Ninov | |||
| Np | 75 | 1908 | data-sort-value="Ogawa, Masataka" | [6] | ||||
| 1846 | data-sort-value="Rose, Heinrich" | Confused with mixtures of the difficult to distinguish niobium and tantalum, extracted from the mineral tantalite.[7] | ||||||
| 77 | 1828 | data-sort-value="Osann, Gottfried" | ||||||
| 76 | 1803 | data-sort-value="Collet-Descotils, Hippolyte-Victor" | ||||||
| 1816 | data-sort-value="Prout, William" | |||||||
| 87 | 1925 | data-sort-value="Dobroserdov, D. K." | ||||||
| Sg | 108 | 1963 | data-sort-value="Cherdyntsev, Victor" | |||||
| 93 | 1939 | data-sort-value="Hulubei, Horia" | Thought to have been present in tantalite ore, actually not present, rather than mis-identified. | |||||
| Ubb | 122 | (Unbibium) | 2008 | data-sort-value="Marinov, Amnon" | ||||
| 1898 | data-sort-value="Crookes, William" | |||||||
| Vi (Vm) | 87 | 1930 | data-sort-value="Allison, Fred" | |||||
| 1862 | data-sort-value="Bahr, J.F." | Another element identified in ores from Ytterby.[8] |