Short answers, pulled from the story.
Stanley Gerald Thompson, Kenneth Street Jr., Albert Ghiorso, and Glenn T. Seaborg discovered californium on the 9th of February 1950 at the University of California Radiation Laboratory in Berkeley. They produced only about 5,000 atoms of the new substance by bombarding curium-242 with 35 MeV alpha particles inside a cyclotron.
Californium acts as a ferromagnet or ferrimagnet below 51 Kelvin and enters an antiferromagnetic state between 48 and 66 Kelvin. Above 66 Kelvin the metal becomes paramagnetic and responds only to external magnetic fields.
Californium-252 emits 2.3 million neutrons per second from just one microgram of material. This intense emission makes it the most potent portable neutron source known to science.
Weighable amounts of californium were first produced in 1954 by irradiating plutonium targets at the Materials Testing Reactor in eastern Idaho. The initial discovery occurred in 1950 but only theoretical quantities existed until this later production.
The half-life of californium-252 is 2.645 years and it disrupts the body's ability to form red blood cells when bioaccumulated in skeletal tissue. About 65% of the element deposited in the skeleton adheres to bone surfaces and causes cancer through ionizing radiation emitted by californium on bone and in the liver.