You'll need to be a serious fan of these puzzles to find over 300 of the things hidden in this jumble. There are no clues as this is test of knowledge as well as determination. Once you get started it's easy enough to find a list of what you are searching for.
Hint:
When all the parts are spread before you on the table you will know each by number.
If you would like an alternative grid with the correct spelling of Aluminium and copyable text:
i1u105muinehtuRCm8S7muidanaVmuiboiN3N al7mPbs5KrmuillahT80yDnegyxO0L711Bae6 NeTum31u1B57r112mMyBO5m352019muoC89nd rkmiu6mur1iu313utro85muinatiTzut3T6iG Bcuminu6Rofsn3iHur9mCuimuidibuRieFld8 Siidpoi55lhimmocomTumigm69m64Fm6dtNo4 mNnaotd3uTTplurnBumiudrgu44u7u2bTniI5 umeCrpoS2m1osetkmiuviioMSienitatsAIu4 iulHuyh2puH1MoHhutnocrb1n1smLdP921Umm niedErRBmi391ghIidirnIa0e4yobso193SuN ocSlAKRhurnoneXPnatee2e3gdnDrLuS9inib timomuinietsniEmitalr7SZomo40p8Ul5enN uruG6eF4nnR7OlmumslFwA8erPgmm2siEetfd leim103mot26AumnumPPassStyruuTcyrnsaF Pmru3mOuli57imuelrCFLaH2inAiio79DigHm pAtinusioe2cSuidAaRar523NomnnM406rndu uenhoi9rPMi4nibb0DgPlP611muei3o16ouMi Unutbc5uCnu1orry2lmm1i391iigtU58muTen HinirlCCrRP1rael68upm1fB0trtcmmLulSnu fmULaarem2hCIBToaiimuM3o1nonAuumiFAit Io1sCCpmu9nealCMtGmui23UrAhe4iiubr8rp mr0mDo1uiesenagnaMsiduLu0nTo0nlire3oe uB6uC1Wiln801iemmmOtrCGo5miR1aetevmlN i36i7stleo10MpuNuumeoeu8HuvuVrbptluh4 n77r0Cllkd21nigmiiunfsm90i2umUoetiiC2 oLma19ayra8ubAmLnhihrEuC7vA4SmNsYSs94 crum91breRnr57uvitdceSiUae45iuPn85e5L rmia00oeBUE935imtenehmmuileH1idu1mnr8 iumS10CBpN4817tucmaTturtheXcmtmn7ugeR ZiyJmuinilodaGniaoc7uie99diBucuUmiape bddmuissatoPRboltrScRrF28ne8iolBurMpm SaoE46muinbuD4rloPNSAe63ee7fsnaiiuPou NleumuiseaCPo7taro6Y9CFsdM7Rsut8llaCi elNmuinamreG14SGP5b11mr01171ann2ul6Ar oaKmuicnarFmuirhoBf14AdaeL8LHUa1heI6t nPCu72ZnegordyH62C8Y5munahtnaLTTTTr4t RaRadiummuiromreviL4ZincTdCmuimorhC6Y
SPOILER:
The names, numbers, and symbols of each element is included. Some overlap completely.