Title: Plutonium | chemical element | Britannica
Headings: Plutonium
Plutonium
chemical element
Element Properties

Content: The power produced from plutonium-238 alpha decay (approximately 0.5 watt per gram) has been used to provide spacecraft electrical power (radioisotope thermoelectric generators [RTGs]) and to provide heat for batteries in spacecraft, such as in the Curiosity rover. Get a Britannica Premium subscription and gain access to exclusive content. Subscribe Now
Plutonium exhibits six forms differing in crystal structure and density (allotropes); the alpha form exists at room temperature. It has the highest electrical resistivity of any metallic element (145 microhm-centimetres). Chemically reactive, it dissolves in acids and can exist in four oxidation states as ions of characteristic colour in aqueous solution: Pu 3+, blue-lavender; Pu 4+, yellow-brown; PuO 2+, pink; PuO 22+, yellow or pink-orange;