Plutonium

Uses of Plutonium
Plutonium-239, which can undergo nuclear chain reactions, is used in nuclear bombs and nuclear reactors Plutonium-238 is used as a long-lived heat and power source for space probes. (Its intrinsic heat output is approximately 0.5 watts per gram.) The Pioneer and Voyager space probes used plutonium-238 nuclear batteries as a power source.