(aangrezi:Neptunium) nepchooniyam avart sarani ka ek tatv hai. nepchooniyam ka pratikanusar 'Np' tatha paramanu sankhya 93 hoti hai. nepchooniyam ka ilektr aaunik vinyas 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 5s2 4d10 5p6 4f14 5d10 6s2 6p6 7s2 6d1 5f4 hota hai. nepchooniyam tatv ki khoj 1940 ee. mean amarika ke kailiphorniya vishvavidyalay ke maikamilan aur ebilasan dvara ki gee. yooreniyam par nyootr aaun ki nabhik pratikriya dvara is tatv ka nirman kiya gaya. rasayanik prayogoan dvara isaki upasthiti ki pushti huee thi.
nepchoon grah ke adhar par isaka nam nepchooniyam rakha gaya. 1942 ee. mean isake doosare samasthanik 237 ki khoj huee, jisaka ardh jivanakal 2.2 x106 varsh hai. yah asamasthanik any yooreniyamottar tatvoan ki apeksha kam ghatak hai. nepchooniyam ke 11 samasthanik jnat haian, jinaki bhar sankhyaean 231, 232, 233, 234, 235, 236, 237, 238, 239, 240 aur 241 haian. nepchooniyam ke rasayanik gun yooreniyam se milate julate haian.
tika tippani aur sandarbh
sanbandhit lekh
varnamala kramanusar lekh khoj