1. Cov xwm txheej twg yuav tsum tau siv los ua tus qauv ntsuas? Teb: (1) High purity, siab tshaj 99.9% (2) Cov khoom xyaw thiab cov tshuaj formula yog zoo ib yam (3) Zoo stability, tsis yooj yim rau nqus dej, tsis yooj yim oxidized los ntawm huab cua, thiab lwm yam. (4) Molar mass yog loj, hnyav. yog qhov loj, thiab qhov hnyav yuam kev tuaj yeem raug txo. 2. Dab tsi yog