选课中心
7099人选课
GRE公开讲座
0元
GMAT公开讲座
0元
一对一体验课
99元
GRE模考网站
10000人
托福TPO模考网站HOT
39209人预约
GRE辅导课程
17537 人
GMAT辅导课程
17537 人
托福辅导课程
17537 人
【定制】1v1
私人订制
资料下载
考前冲刺
扫码关注掌握一手留学资讯
回复XDF免费领
水平测试和备考资料
扫码关注公众号
【GRE阅读题目解析:化学反应与温度的规律】GRE考试考什么?GRE阅读是重点。新东方在线GRE频道为大家带来GRE阅读题目解析:化学反应与温度的规律,答案见下一页,希望对大家GRE备考有所帮助。更多精彩尽请关注新东方在线GRE频道!
查看全部:GRE阅读答案解析(汇总)
GRE阅读题目解析:化学反应与温度的规律
P2
About a century ago, the Swedish physical scientist Arrhenius proposed a law of classical chemistry that relates chemical reaction rate to temperature. According to the Arrhenius equation, chemical reaction are increasingly unlikely to occur as temperatures approach absolute zero, and at absolute zero (zero degrees Kelvin, or minus 273 degrees Celsius) reactions stop. However, recent experimental evidence reveals that although the Arrhenius equation is generally accurate in describing the kind of chemical reaction that occurs at relatively high temperatures, at temperatures closer to zero a quantum-mechanical effect known as tunneling comes into play; this effect accounts for chemical reactions that are forbidden by the principles of classical chemistry. Specifically, entire molecules can "tunnel" through the barriers of repulsive forces from other molecules and chemically react even though these molecules do not have sufficient energy, according to classical chemistry, to overcome the repulsive barrier.
The rate of any chemical reaction, regardless of the temperature at which it takes place, usually depends on a very important characteristic known as its activation energy. Any molecule can be imagined to reside at the bottom of a so-called potential well of energy. A chemical reaction corresponds to the transition of a molecule from the bottom of one potential well to the bottom of another. In classical chemistry, such a transition can be accomplished only by going over the potential barrier between the wells, the height of which remains constant and is called the activation energy of the reaction. In tunneling, the reacting molecules tunnel from the bottom of one to the bottom of another well without having to rise over the barrier between the two wells. Recently researchers have developed the concept of tunneling temperature: the temperature below which tunneling transitions greatly outnumber Arrhenius transitions, and classical mechanics gives way to its quantum counterpart.
This tunneling phenomenon at very low temperatures suggested my hypothesis about a cold prehistory of life: the formation of rather complex organic molecules in the deep cold of outer space, where temperatures usually reach only a few degrees Kelvin. Cosmic rays (high-energy protons and other particles) might trigger the synthesis of simple molecules, such as interstellar formaldehyde, in dark clouds of interstellar dust. Afterward complex organic molecules would be formed, slowly but surely, by means of tunneling. After I offered my hypothesis, Hoyle and Wickramasinghe argued that molecules of interstellar formaldehyde have indeed evolved into stable polysaccharides such as cellulose and starch. Their conclusions, although strongly disputed, have generated excitement among investigators such as myself who are proposing that the galactic clouds are the places where the prebiological evolution of compounds necessary to life occurred.
2.According to the passage, classical chemical reactions and tunneling reactions are alike in which of the following ways?
(A) In both types of reactions, reacting molecules have to rise over the barrier between the two wells.
(B) In both types of reactions, a transition is made from the bottom of one potential well to the bottom of another.
(C) In neither type of reaction does the height of the barrier between the wells remain constant.
(D) In neither type of reaction does the rate of a chemical reaction depend on its activation energy.
(E) In both types of reactions, reacting molecules are able to go through the barrier between the two wells.
3.The author's hypothesis concerning the cold prehistory of life would be most weakened if which of the following were true?
(A)Cosmic rays are unlikely to trigger the formation of simple molecules.
(B)Tunneling occurs only in a narrow band of temperatures around zero degrees Kelvin.
(C)The synthesis of interstellar formaldehyde can be activated by means other than cosmic rays.
(D)Simple molecules can be synthesized by means of tunneling.
(E)Classical chemical reactions do not occur at temperatures close to absolute zero.
4.Which of the following best describes the hypothesis of Hoyle and Wickramasinghe as it is presented in the passage?
(A) Cosmic rays can directly synthesize complex organic molecules.
(B) The galactic clouds are the places where prebiological evolution of compounds necessary to life occurred.
(C) Interstellar formaldehyde can be synthesized by tunneling.
(D) Molecules of interstellar formaldehyde can evolve into complex organic molecules.
(E) Complex organic molecules can be synthesized from stable polysaccharides such as cellulose and starch.
5.Which of the following best describes the organization of the first two paragraphs of the passage?
(A) The author cites a basic principle of classical chemistry and then describes the research from which that principle was developed.
(B) The author cites an apparent contradiction to the principles of classical chemistry and then explains the process of a chemical reaction to show there is in fact no contradiction.
(C) the author describes the role of heat in chemical reactions and then offers a detailed explanation of its function.
(D) The author presents a law of classical chemistry in order to introduce a kind of chemical reaction that differs from it and then explains the essential difference between the two.
(E) The author presents the fundamental rules of classical chemistry in order to introduce an explanation of a specific chemical reaction.
资料下载
GRE佛脚2024增补包含最新热词与六选二整理
发布时间:2022-06-06添加新东方在线美研助教号
回复【资料】获取
GRE-PPO模考完整套题+解析资料下载
发布时间:2022-06-06添加新东方在线美研助教号
回复【资料】获取
GRE佛脚词汇表网络版资料下载
发布时间:2022-05-21添加新东方在线美研助教号
回复【资料】获取
2024GRE佛脚填空机经系列资料下载
发布时间:2022-04-15添加新东方在线美研助教号
回复【资料】获取
2024GRE佛脚阅读系列资料下载
发布时间:2022-04-15添加新东方在线美研助教号
回复【资料】获取
2024杨鹏阅读难句(GMAT+GRE)教程资料下载
发布时间:2022-04-15添加新东方在线美研助教号
回复【资料】获取
GRE PPO模考完整练习题(答案)
发布时间:2019-12-10添加新东方在线美研助教号
回复【资料】获取
GRE写作题库解析【Issue/Argument】
发布时间:2019-12-10添加新东方在线美研助教号
回复【资料】获取
GRE阅读机经及官方真题资料练习
发布时间:2019-12-10关注新东方在线美研订阅号
回复【GRE】获取
GRE填空机经佛脚系列资料持续更新…
发布时间:2019-12-10添加新东方在线美研助教号
回复【资料】获取
GRE佛脚词汇修订版PDF电子版下载
发布时间:2019-12-10添加新东方在线美研助教号
回复【资料】获取
【提升英语必看】英语记录片/演讲/美剧合集
发布时间:2019-11-27添加新东方在线美研助教号
回复【资料】获取
《华尔街日报》、《纽约时报》英文报刊合集
发布时间:2019-11-27添加新东方在线美研助教号
回复【资料】获取
【必看】美国研究生申请注意事项
发布时间:2019-11-27添加新东方在线美研助教号
回复【资料】获取
美国研究生录取分数&截止日期信息汇总
发布时间:2019-11-27添加新东方在线美研助教号
回复【资料】获取
2020美国研究生热门专业院校排名
发布时间:2019-11-27添加新东方在线美研助教号
回复【资料】获取
GRE模考套题、机经汇总
发布时间:2019-11-27添加新东方在线美研助教号
回复【资料】获取
添加美研助教号,
回复【GRE】获取备考必看资料包
推荐阅读
更多>>备考GRE,对大部分同学来说也是一个新挑战,尤其是阅读部分,如何在有限的时间内大幅提高阅读速度呢? 快来本文看看吧。
本文今天为大家带来的是gre考试中easy等级难度的阅读片段,一起来看看吧!
2022年3月13-19日GRE阅读题回忆及答案(六)来啦,来本文和新东方在线GRE一起来看看详细信息吧。
2022年3月13-19日GRE阅读题回忆及答案(五)来啦,来本文和新东方在线GRE一起来看看详细信息吧。
2022年3月13-19日GRE阅读题回忆及答案(四)来啦,来本文和新东方在线GRE一起来看看详细信息吧。
2022年3月13-19日GRE阅读题回忆及答案(三)来啦,来本文和新东方在线GRE一起来看看详细信息吧。
2022年3月13-19日GRE阅读题回忆及答案(二)来啦,来本文和新东方在线GRE一起来看看详细信息吧。
2022年3月13-19日GRE阅读题回忆及答案(一)来啦,来本文和新东方在线GRE一起来看看详细信息吧。
2022年2月13日GRE阅读题回忆及答案来啦,来本文和新东方在线GRE一起来看看详细信息吧。
2022年2月13日GRE阅读题回忆及答案来啦,来本文和新东方在线GRE一起来看看详细信息吧。
添加美研助教号,
回复【GRE】获取备考必看资料包
资料下载
更多>>添加新东方在线美研助教号
回复【资料】获取
添加新东方在线美研助教号
回复【资料】获取
添加新东方在线美研助教号
回复【资料】获取
添加新东方在线美研助教号
回复【资料】获取
添加新东方在线美研助教号
回复【资料】获取
添加新东方在线美研助教号
回复【资料】获取
添加新东方在线美研助教号
回复【资料】获取
添加新东方在线美研助教号
回复【资料】获取
关注新东方在线美研订阅号
回复【GRE】获取
添加新东方在线美研助教号
回复【资料】获取
添加新东方在线美研助教号
回复【资料】获取
添加新东方在线美研助教号
回复【资料】获取
添加新东方在线美研助教号
回复【资料】获取
添加新东方在线美研助教号
回复【资料】获取
添加新东方在线美研助教号
回复【资料】获取
添加新东方在线美研助教号
回复【资料】获取
添加新东方在线美研助教号
回复【资料】获取
阅读排行榜
相关内容