plutonium

युरेनियमभन्दा भारी ठोस चाँदीखैरो रेडियोधर्मी तत्त्व, जसका परमाणु न्युट्रोन प्रहारले टुक्रिन्छन्; अयस्कमा अल्प मात्रामा, प्रायः आणविक भट्टीमा बनाइने; 13 ज्ञात समस्थानिकमध्ये प्लुटोनियम-239 प्रमुख

a solid silvery grey radioactive transuranic element whose atoms can be split when bombarded with neutrons; found in minute quantities in uranium ores but is usually synthesized in nuclear reactors; 13 isotopes are known with the most important being plutonium 239