History
The discovery of all elements in the group led to controversies. The verification of those discoveries was difficult due to similarity of vanadium and group 6 element chromium, the chemical similarity of niobium and tantalum and the complicated setup which was necessary to produce a few atoms of dubnium.
Read more about this topic: Group 5 Element
Famous quotes containing the word history:
“Boys forget what their country means by just reading “the land of the free” in history books. Then they get to be men, they forget even more. Liberty’s too precious a thing to be buried in books.”
—Sidney Buchman (1902–1975)
“America is, therefore the land of the future, where, in the ages that lie before us, the burden of the World’s history shall reveal itself. It is a land of desire for all those who are weary of the historical lumber-room of Old Europe.”
—Georg Wilhelm Friedrich Hegel (1770–1831)
“Psychology keeps trying to vindicate human nature. History keeps undermining the effort.”
—Mason Cooley (b. 1927)