Which of the following silica gel as adsorbent in TLC, contains neither inorganic adhesive material(gypsum ustum) nor fluorescence indicator? A: Silica gel H B: Silica gel G C: Silica gel GF254 D: None of above

‏The most expensive glass is .‏ A: Soda-lime B: Borosilicate glass C: Lead-alkali silica glass D: Fused silica glass

The most expensive glass is . A: Soda-lime B: Borosilicate glass C: Lead-alkali silica glass D: Fused silica glass

silica gel A: 硅胶 B: % C: @

Silica can account for over of the respirable dust sample by weight

Measure the rate of how the silica gel the moisture. A: absorb (v.) B: absorption (n.)

You must insert …….bags inside cartons. A: carbon B: gel C: silica gel

Isolate the facility from the general mine air circuit is the methods for reducing exposure to silica dust.

Silica gel is belongs to ___ adsorbent. A: non-polar B: polar C: semi-chemical D: alkaline E: chemical

What are the the form of silica？ A: alpha quartz B: beta quartz C: tridymite D: Normal atmospheric dusts