. "0"^^ . . "a highly fissionable isotope of plutonium that is used in atomic weapons and as a reactor fuel; produced by irradiating uranium 238 with slow electrons"@en-us . . . . . . "110497127"@en-us . "14650137-n"^^ . . . "plutonium 239"^^ . "0"^^ . "plutonium 239"@en-us . "113811429"@en-us . "114650137"^^ . .