ilektraun ya vidyudanu (praacheen yoonaani bhaasha: ἤaaλaaεaaκaaτaaρaaοaaν, laitin, angreji, French, Spanish: Electron, jarman: Elektron) rinaatmak vaidyut aavesh yukt moolabhoot upaparamaanavik kan hai. yeh parmaanu me naabhik ke chaaro or chakkar lagaata hain. iska dravyamaan sabse chhote parmaanu (haaidrojan) se bhi hajaaraguna kam hota hai. paramparaagat rup se iske aavesh ko rinaatmak maana jaata hai aur iska maan -1 parmaanu ikaai (e) nirdhaarit kiya gaya hai. is par 1.6E-19 koolaamb parimaan ka rin aavesh hota hai. iska dravyamaan 9.11E−31 kigra hota hai jo protaun ke dravyamaan ka lagbhag 1837 vaan bhaag hai. kisi udaaseen parmaanu mein vidyudanuon ki sankhya aur protaanon ki sankhya samaan hoti hai. inki aantarik sanrachana gyaat naheen hai isliye ise praaya:moolabhoot kan maana jaata hai. inki aantarik prachakran 1/2 hoti hai, at: yeh farmeeya hote hai. ilektraun ka pratiknpojeetraun kahalaata hai. dravyamaan ke alaava pojeetraun ke saare gun yatha aavesh ityaadi ilektraun ke bilkul vipreet hote hai. jab ilektraun aur pojeetraun ki takkar hoti hai to donno poornat: nasht ho jaate hai evam do fotaun utpann hoti hai.
ilektraun, leptaun parivaar ke pratham peedhi ka sadasya hai, jo ki gurutvaakarshan, vidyut chumbakatv evam durbal prabhaav sabhi mein bhoomika nibhaata hai. ilektraun kan evam tarang dono tarah ke vyavahaar pradarshit karta hai. beeta-kshaya ke rup me yeh kan jaisa vyavahaar karta hai, jabki yang ka double slit prayog (Young's double slit experiment) mein iska kiran jaisa vyavahaar siddh hua. choonki iska saankhyikeeya vyavahaar farmion hota hai aur yeh pauli eksaklyusan sidhdaant ka paalan karta hai.
iris bhautikvid George jaunaston stoni (George Johnstone Stoney) ne 1894 mein elektron naam ka sujhaav diya tha. vidyudanu ki kan ke rup mein pehchaan 1897 mein J J thaumasan (J J Thomson) aur unki vilaayati bhautikvid dal ne ki thi.
kai bhautikeeya ghatnaaen jaise-vidhyut, chumbakatv, ushma chaalakata mein vidyudanu ki aham bhoomika hoti hai. jab vidyudanu tvarit hota hai to yeh fotaan ke rup meinoorja ka avashoshan ya utsarjan karta hai.protaun va nyootraun ke saath milkar yahparmaanu ka nirmaan karta hai.parmaanu ke kul dravyamaan mein vidyudanu ka hissa kam se kam 0.06 pratishat hota hai. vidyudanu aur protaun ke beech lagne vaale kulaamb bal (coulomb force) ke kaaran vidyudanu parmaanu se bandha hota hai. do ya do se adhik paramaanuon ke vidyudanuon ke aapasi aadaan-pradaan ya saajhedaari ke kaaran raasaayanik bandh bante hai.
brahmaand mein adhiktar vidyudanuon ka nirmaan big-bang ke dauraan hua hai, inka nirmaan rediyodharmi samasthaanik (radioactive isotope) se beeta-kshaya aur antariksheeya kirno (cosmic ray) ke vaayumandal mein pravesh ke dauraan uchch oorja takkar ke kaaran bhi hota hai.
