[{"from": "human", "value": "Provide a description of this molecule. [240Pu]"}, {"from": "gpt", "value": "The molecule is an element with the symbol Pu and atomic number 94. It is a rare transuranic radioactive element that normally exhibits six allotropes and four oxidation states. It is also a radioactive poison that accumulates in bone marrow. Plutonium-240 has a high rate of spontaneous fission, raising the background neutron radiation of plutonium containing it. Plutonium is graded by proportion of Pu-240. Lower grades are less suited for nuclear weapons and thermal reactors but can fuel fast reactors. Pu-240 is not fissile, but is fertile material like U-238. (L1840)"}]