It remains to be seen, he said, whether concerns about the use of an“air sensitive” substance outweigh concerns about the costs and environmental impact of precious metals. 以上就是关于这位化学家寻找点石成金的SAT文章阅读材料的故事,字数不是很多,但是非常完整,而且生词量也不是很大。大家完全可以...
搜索智能精选 题目 A chemical ___ is any aspect of a substance which is only seen by means of a chemical reaction. (property)答案 property
The substance that speeds up a chemical reaction without being consumed in the reaction is called a ___. A. catalyst B. reactant C. product D. solute 相关知识点: 试题来源: 解析 A。catalyst 是催化剂,能加快化学反应速率但自身在反应前后不被消耗;reactant 是反应物;product 是产物;solute 是溶...
A substance that speeds up a chemical reaction without being changed itself is called a ___. A. reactant B. product C. catalyst D. solvent 相关知识点: 试题来源: 解析 C。选项 A“reactant”指反应物;选项 B“product”指生成物;选项 D“solvent”指溶剂。能加快化学反应速率而自身质量和化学...
When a substance undergoes a chemical reaction and the mass of the reactants is greater than the mass of the products, what can be concluded? A. Some matter was destroyed. B. Some matter was created. C. Some matter was converted into energy. D. Some matter was lost as gas. ...
In this chemical reaction, the substance changes ___. A. complete B. completely C. completeness D. completing 相关知识点: 试题来源: 解析 B。本题考查词性。“change”是动词,需要用副词修饰,A 是形容词,C 是名词,D 是现在分词。“completely”是副词,修饰“change”。
In a chemical reaction, the amount of substance G is twice that of substance H. If there are 8 grams of substance H, how many grams of substance G are there? A. 4 grams B. 8 grams C. 16 grams D. 32 grams 相关知识点:
If there are 6 moles of substance B, how many moles of substance A are there? A. 2 moles B. 4 moles C. 6 moles D. 8 moles 相关知识点: 试题来源: 解析 B。因为 A 和 B 的比例是 2:3,B 有 6 摩尔,设 A 有 x 摩尔,则 2:3 = x:6,解得 x = 4。
The reaction zone is\nmonitored for the presence of the tagging substance, and when the\nsubstance is detected a trigger signal is generated to signal the\nstart of the reaction. By including a tagging substance with each\ncomponent of the reaction and by monitoring the reaction zone for\n...
The substance that speeds up a chemical reaction without being consumed itself is called: A. Reactant B. Product C. Catalyst D. Substrate 相关知识点: 试题来源: 解析 C。加快化学反应速率但自身不被消耗的物质称为催化剂(Catalyst)。“Reactant”是反应物;“Product”是产物;“Substrate”在酶促反应...