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How did Glenn T. Seaborg and his colleagues discover plutonium?

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A color-coded periodic table of the elements displays each element's symbol and atomic number, with categories such as alkali metals, noble gases, halogens, transition metals, and actinoid elements distinguished by different background colors. — transuranium element Modern version of the periodic table of the elements (printable).

Glenn T. Seaborg, along with his colleagues Joseph W. Kennedy and Arthur C. Wahl, discovered plutonium (element 94) on February 23, 1941, at the University of California, Berkeley.123

The discovery followed the earlier identification of neptunium (element 93) by Edwin McMillan and Philip Abelson, who had inferred that neptunium would decay into element 94. Building on this, Seaborg’s team produced and chemically identified the new element.132

Initially, studies were conducted on a tracer scale with amounts too small to be weighed. By August 1942, Seaborg, Burris B. Cunningham, and Louis B. Werner successfully isolated the first visible amount of plutonium. Seaborg later played a critical role in the Manhattan Project, where he was responsible for scaling up the extraction of plutonium from laboratory quantities to industrial-scale production at the Hanford Engineering Works.2

Are you interested in learning more about the actinoid series or how plutonium is used in nuclear reactors?