In 1809, the English chemist William Hyde Wollaston wrongly concluded that tantalum and columbium were identical.

In 1809, the English chemist William Hyde Wollaston compared the oxides derived from both columbium — columbite, with a density 5. 918 g / cm < sup > 3 </ sup >, and tantalum — tantalite, with a density over 8 g / cm < sup > 3 </ sup >, and concluded that the two oxides, despite the significant difference in density, were identical ; thus he kept the name tantalum.

In 1809, the English chemist William Hyde Wollaston compared the oxides derived from both columbium — columbite, with a density 5. 918 g / cm < sup > 3 </ sup >, and tantalum — tantalite, with a density 7. 935 g / cm < sup > 3 </ sup >, and concluded that the two oxides, despite their difference in measured density, were identical.

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