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
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“Indeed, the Englishman’s history of New England commences only when it ceases to be New France.”
—Henry David Thoreau (1817–1862)
“What you don’t understand is that it is possible to be an atheist, it is possible not to know if God exists or why He should, and yet to believe that man does not live in a state of nature but in history, and that history as we know it now began with Christ, it was founded by Him on the Gospels.”
—Boris Pasternak (1890–1960)
“Literary works cannot be taken over like factories, or literary forms of expression like industrial methods. Realist writing, of which history offers many widely varying examples, is likewise conditioned by the question of how, when and for what class it is made use of.”
—Bertolt Brecht (1898–1956)