Testing for Gold's purity, involves the use of strong acids. Gold is a noble metal that is resistant to change by corrosion, oxidation, or acids. In order to distinguish gold from other base metals, the gold-containing item is rubbed on a black stone/surface which will leave a visible mark. Nitric A

There are multiple biological safety cabinet classes. But what are they and how are they different? Biological safety cabinet classes (or biosafety cabinet classes) are categories describing how the cabinet works and what it protects. These “categories” are Class I, Class II and Class III.Class IA C

The operation of the mini centrifuge is very simple, just put the centrifuge tube, cover the lid and press the switch, and the rotor can quickly reach the maximum speed. Although the mini centrifuge is small, we should also pay attention when using it. The correct operation method can reduce the dam