What concepts are described in the following sentence?

"Glenn T. Seaborg, Arthur C. Wahl, W. Kennedy and E.M. McMillan bombarded uranium with deuterons, and a new element, Plutonium was discovered."

Return the answer as pairs of triples.
Plutonium NOTES Prepared by bombardment of uranium with deuterons.
Plutonium OBSERVER Glenn T. Seaborg, Arthur C. Wahl, W. Kennedy and E.M. McMillan