當(dāng)前位置: 首頁 > 職稱英語 > 職稱英語歷年試題 > 2012年職稱英語考試試題及答案-理工類A級概括大意

2012年職稱英語考試試題及答案-理工類A級概括大意

更新時間:2015-12-10 11:50:58 來源:|0 瀏覽0收藏0

  2012年職稱英語考試已經(jīng)結(jié)束,環(huán)球網(wǎng)校整理發(fā)布2012年職稱英語考試?yán)砉ゎ怉級(試卷代碼11)試題及答案,敬請關(guān)注!

      環(huán)球網(wǎng)校2012年職稱英語考試押中45分原題,么建華教授獨(dú)家解析2012年職稱英語考試

  三、概括大意與完成句子

Learn about Noble Gases(惰性氣體)

  1  Have you ever ridden on a balloon? Many tourist spots offer balloon rides in order for people to see the beauty of a place from above. A balloon contains a noble gas called helium(氦). Formerly, balloons contained hydrogen but hydrogen is very flammable and dangerous when uncontrolled. Therefore, people shifted to helium, which is safer. Helium is safe because it has the properties of the noble gases.

  2  People once believed that noble gases couldn’t chemically react at all. For this reason, they were called inert gases(惰性氣體). They were also listed under Group 0 in the old periodic table because scientists believed that the gases have zero valence(價) electrons in their outer shell. This was later proven to be untrue when some noble gas compounds were discovered.

  3  The gases are elements, which share similar properties. These properties include being monoatomic, colorless, odorless, being able to conduct electricity, and having low chemical reactivity. Noble gases include Helium, Neon, Argon, Krypton, Xenon and Radon. These are all found in Group 18, in the rightmost column of the periodic table. If you look at the periodic table, you will notice that these elements are the only ones, which do not have a charge. Helium has the lowest molecular(分子的) weight while Radon is the heaviest.

  4 Remember that chemical reactions occur because atoms have valence electrons, which are electrons in their outer shell. When the outer shell is “unfilled” or the required number of electrons is not yet complete, the atom is more reactive. Noble gases have a full outer shell, meaning that they have complete electrons in their outer shell. This complete number varies. For instance, the outer shell of Helium has 2 valence electrons while the outer shell of Xenon has 8 electrons. Nowadays, there remains to be a few noble gases because of the low chemical reactivity of these said gases.

  A. what is the periodic table?B. What are noble gases?C. What causes the low chemical reactivity of noble gases? D. How were noble gases discovered?E. How were noble gases understood in the past?F. what are the applications of noble gases?

  5 because of their properties, noble gases have many important applications. They are widely used in medicine and industries. For instance, liquid Helium is used for superconducting magnets(磁體). These magnets are very important in physics and medicine. When a doctor suspects that a person’s brain has been damaged, he might request for Magnetic Resonance Imaging(MRI). MRI allows the doctor to “see” the brain, without operating on the patient.

  23. paragraph 2__ E ___

  24. paragraph 3__ B____

  25. paragraph 4___C____

  26. paragraph 5___F_____

  27. Noble gases are not very chemically

  答案:A

  28. Among the elements of noble gases Helium is the

  答案:B

  29. The required number of electrons in noble gases’ outer shell is

  答案:D

  30. MRI may make operating on the patient

  答案:F

  A. reactive B. lightestC. important D. complete E. flammableF. unnecessary

更多相關(guān)信息請關(guān)注:  

2013年全國職稱英語等級考試網(wǎng)絡(luò)輔導(dǎo)招生簡章
2012年全國職稱英語成績查詢時間及短息提醒預(yù)定
環(huán)球么建華教授獨(dú)家解析2012年職稱英語考試
環(huán)球網(wǎng)校2012年職稱英語考試押中45分原題
環(huán)球首發(fā)2012年職稱英語考試真題與答案匯總

分享到: 編輯:環(huán)球網(wǎng)校

資料下載 精選課程 老師直播 真題練習(xí)

職稱英語資格查詢

職稱英語歷年真題下載 更多

職稱英語每日一練 打卡日歷

0
累計打卡
0
打卡人數(shù)
去打卡

預(yù)計用時3分鐘

環(huán)球網(wǎng)校移動課堂APP 直播、聽課。職達(dá)未來!

安卓版

下載

iPhone版

下載

返回頂部