TPO 16 DEVELOPMENT OF THE PERIODIC T … - 英檢

※ 引述《tom192180 (tom510558)》之銘言：
: 不好意思，想請問大家這篇。
: 第二段:

網路上資源真的很多
建議遇到不熟悉的題目大家要去瞭解一下
ETS題目重複性驚人的高
8/28 閱讀又出現 Louis Daguerre 與攝影藝術
出現在TPO 22的閱讀第二篇 The Birth of Photography
所以比起機經 TPO的內容更要熟悉

GRE有提到攝影的文章
吳中東 A84-2(北美) 攝影藝術是主觀還是客觀
A9504(中國) 攝影是不是藝術
The Birth of Photography第7段 其實就跟A9504的內容一模一樣, 都在討論攝影藝術的價值



言歸正傳
週期表有背過的同學都知道 有橫背(依照原子序= 質子數) 與直的背(化學性質相似的群)
這整篇文章就是在講週表的故事
wiki有張圖
http://en.wikipedia.org/wiki/File:Mendeleev%27s_1869_periodic_table.png
請google
Periodic table

看到這張圖的O 氧 標示16 就知道這早期的週期表跟今日不同
寫的是atomic mass number
所以發生Te = 128(圖中還打了驚嘆號) I=127
所以文中說明
tellurium comes before iodine in the periodic table (雖然當時的排列是直的)
但是後面一大堆意思就是要說
今日我們已經知道要依照 atomic number 來排列
因為主要的化學性質與atomic number 有關
A : atomic mass number. Z : atomic number.
A = Z + N (質量數=質子數+中子數)


wiki寫的很清楚 有兩個重點
當時有兩人提出類似的週期表
Russian chemistry professor Dmitri Ivanovich Mendeleev and
German chemist [Julius Lothar Meyer] independently published their
periodic tables in 1869 and 1870, respectively. They both constructed their
tables in a similar manner: by listing the elements in a row or column in
order of atomic weight and starting a new row or column when the
characteristics of the elements began to repeat.[25]

The success of Mendeleev's table came from two decisions he made:
有first要注意 至少有兩點
The first was to leave gaps in the table when it seemed that the
corresponding element had not yet been discovered.[26]
有but 的句子要注意
Mendeleev was not the first chemist to do so, but he was the first to be
recognized as using the trends in his periodic table to predict the
properties of those missing elements, such as gallium and germanium.[27]
出現第二點
The second decision was to occasionally ignore the order suggested
by the atomic weights and switch adjacent elements, such as cobalt and
nickel, to better classify them into chemical families.

這個跟我上面說的一樣 原來排列的依據應該是increasing atomic number
而不是atomic mass number
With the development of theories of atomic structure, it became apparent
that Mendeleev had listed the elements in order of increasing atomic number.
[28]

這個不是英文的問題
其實只要要複習一下國中理化的週期表
ETS的內容大致就是國中生物.理化.地球科學
有不熟的在練習英文之餘可以多多複習
瞭解觀念之後很多閱讀文章就不用慢慢讀了

: When the German chemist Lothar Meyer and (independently) the Russian Dmitry
: Mendeleyev first introduced the periodic table in 1869-70, one-third of the
: naturally occurring chemical elements had not yet been discovered. Yet both
: chemists were sufficiently farsighted to leave gaps where their analyses of
: periodic physical and chemical properties indicated that new elements should
: be located. Mendeleyev was bolder than Meyer and even assumed that if a
: measured atomic mass put an element in the wrong place in the table, the
: atomic mass was wrong. In some cases this was true. Indium, for example, had
: previously been assigned an atomic mass between those of arsenic and
: selenium. Because there is no space in the periodic table between these two
: elements, Mendeleyev suggested that the atomic mass of indium be changed to a
: completely different value, where it would fill an empty space between
: cadmium and tin. In fact, subsequent work has shown that in a periodic table,
: elements should not be ordered strictly by atomic mass. For example,
: tellurium comes before iodine in the periodic table, even though its atomic
: mass is slightly greater. Such anomalies are due to the relative abundance of
: the "isotopes" or varieties of each element. All the isotopes of a given
: element have the same number of protons, but differ in their number of
: neutrons, and hence in their atomic mass. The isotopes of a given element
: have the same chemical properties but slightly different physical properties.
: We now know that atomic number (the number of protons in the nucleus), not
: atomic mass number (the number of protons and neutrons), determines chemical
: behavior.
: 6. It can be inferred from paragraph 2 that tellurium comes before iodine in
: the periodic table even though tellurium's atomic mass is slightly greater
: because
: ○iodine is less common than tellurium
: ○both iodine and tellurium have no isotopes
: ○the chemical behavior of tellurium is highly variable
: ○the atomic number of tellurium is smaller than that of iodine
: 答案是D， 可是要從哪推論出來，我左看右看都看不出端倪= =

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