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:
“The history of our era is the nauseating and repulsive history of the crucifixion of the procreative body for the glorification of the spirit.”
—D.H. (David Herbert)
“In all history no class has been enfranchised without some selfish motive underlying. If to-day we could prove to Republicans or Democrats that every woman would vote for their party, we should be enfranchised.”
—Carrie Chapman Catt (1859–1947)
“The steps toward the emancipation of women are first intellectual, then industrial, lastly legal and political. Great strides in the first two of these stages already have been made of millions of women who do not yet perceive that it is surely carrying them towards the last.”
—Ellen Battelle Dietrick, U.S. suffragist. As quoted in History of Woman Suffrage, vol. 4, ch. 13, by Susan B. Anthony and Ida Husted Harper (1902)