Short answers, pulled from the story.
Glenn T. Seaborg, Albert Ghiorso, Stanley Gerald Thompson, and Kenneth Street Jr. discovered berkelium in December 1949 at the Lawrence Radiation Laboratory in California. They created berkelium-243 by bombarding americium-241 with alpha particles using a 60-inch cyclotron.
Scientists produce measurable amounts of berkelium at the Oak Ridge National Laboratory in Tennessee and the Research Institute of Atomic Reactors in Dimitrovgrad, Russia. Since 1967, facilities have generated just over one gram of berkelium-249 through specialized nuclear reactors.
Berkelium measures 14.78 grams per cubic centimeter and melts at 986 degrees Celsius while adopting an alpha form with hexagonal symmetry under ambient conditions. Compressing this structure to 7 gigapascals transforms it into a beta modification with face-centered cubic symmetry before creating an orthorhombic gamma phase up to 25 gigapascals.
Nineteen isotopes of berkelium range from mass number 233 to 253 with all forms exhibiting radioactivity. Berkelium-247 stands as the longest-lived isotope with a duration exceeding 1,380 years.
A 22-milligram sample prepared at Oak Ridge enabled the first creation of tennessine at Russia's Joint Institute for Nuclear Research. This achievement required bombarding the target with calcium-48 ions over a period lasting 150 days to produce six atoms of element 117.