- Cobalt Powder
- 2016-11-01 16:39
- Cobalt is a Block D, Group 9, Period 4 element. The number of electrons in each of Cobalt's shells is 2, 8, 15, 2 and it
- PET Polyster
- 2016-10-28 01:56
- PET polysterItem: PET polyster1. High quality and competitive price2. White granular3. As shown in figure is PET goods a