Erratic is to predictable as exorbitant is to______. () A: small B: implicit C: productive D: absorbent E: reasonable

In the event of a small bunker oil spill on deck occurring while bunkering, you should ____. A.wash down the area immediately with a fire hose B.wash down the area with kerosene C.cover the area with absorbent material D.cover the area with foam

Which of the following is correct for TLC using silica gel as absorbent? A: Higher the absorption activity of absorbent. larger k and smaller Rf B: Higher the absorption activity of absorbent. larger k and larger Rf C: Stronger the polarity of solvent. larger k and smaller Rf D: Weaker the polarity of solvent. larger k an d larger Rf

Which one is correct for description of TLC using silica gel as absorbent? A: Higher the absorption activity of absorbent. larger k and smaller Rf B: Higher the absorption activity of absorbent. larger k and larger Rf C: Stronger the polarity of solvent. larger k and smaller Rf D: Stronger the polarity of solvent. larger k and larger Rf

下列哪些关于吸附作用的说法是正确的？ A: 物质从流体相 (气体或液体) 浓缩到固体表面从而达到分离的过程称为吸附作用 (adsorption), 在表面上能发生吸附作用的固体微粒称为吸附剂 (absorbent),而被吸附的物质称为吸附物 (adsorbate) B: 如果在吸附剂和吸附物之间有电子的转移, 发生化学反应而产生化学键, 这种吸附称为化学吸附 C: 当吸附剂和吸附物之间作用力是通过分子间引力 ( 范德华力) 产生的吸附称为物理吸附 D: 物理吸附是可逆的, 可以成单分子层吸附或多分子层吸附, 选择性较差