请输入或粘贴题目内容
搜题
拍照、语音搜题，请扫码下载APP
题目内容
（请给出正确答案）
答案
更多“Periodic table is divided into eight vertical columns known as A) ______ and seven horizontal rows k”相关的问题
第1题
请在第____处填上正确答案。
A. There have been many attempts to redesign the periodic table since Dmitri Mendeleev drew it up in 1871．
B. Railsback has still ordered the elements according to the number of protons they have．
C. “I imagine this would be good for undergraduates．”
D. Railsback has listed some elements more than once．
E. And the size of element’s symbol reflects how much of it is found in the Earth’s crust．
F. The traditional periodic table was well drawn．
第2题
Reinventing the Table
An earth scientist has rejigged the periodic table to make chemistry simpler to teach to students.
(46)But Bruce Railsback from the University of Georgia3 says he is the first to create a table that breaks with tradition and shows the ions of each element rather than just the elements themselves.
"I got tired of breaking my arms trying to explain the periodic table to earth students," he says, criss-crossing his hands in the air and pointing to different bits of a traditional table.(47)But he has added contour lines to charge density, helping to explain which ions react with which.
"Geochemists just want an intuitive sense of what's going on with the elements," says Albert Galy from the University of Cambridge4,(48).
(49)He explains that sulphur, for example, shows up in three different spots -- one for sulphide, which is found in minerals, one for sulphite, and one for sulphate, which is found in sea salt, for instance.
He has also included symbols to show which ions are nutrients, and which are common in soil or water.(50).
A. There have been many attempts to redesign the periodic table since Dmitri Mendeleev2 drew it up in 1871.
B. Railsback has still ordered the elements according to the number of protons they have.
C. "I imagine this would be good for undergraduates."
D. Railsback has listed some elements more than once.
E And the size of element's symbol reflects how much of it is found in the Earth's crust.
F The traditional periodic table was well drawn.
第3题
The【C1】______took a sharp upward leap with the invention of writing, but even【C2】______it remained painfully slow for several centuries. The next great leap forward【C3】______knowledge acquisition did not occur【C4】______the invention of movable type in the 15th century by Gutenberg and others.【C5】______to 1500, by the most optimistic【C6】______Europe was producing books at a rate of 1000 titles per year. This means that it【C7】______a full century to produce a library of 100,000 titles. By 1950, four and a half【C8】______later, the rate had accelerated so sharply that Europe was producing 120,000 titles a year.【C9】______once took a century now took only ten months. By 1960, a【C10】______decade later, the rate had made another significant jump,【C11】______a century's work could be finished in seven and a half months.【C12】______, by the midsixties, the output of books on a world【C13】______, Europe included, approached the prodigious(巨大的)figure of 900 titles per day.
One can【C14】______argue that every book is a net gain for the advancement of knowledge. Nevertheless we find that the accelerative【C15】______in book publication does, in fact, crudely【C16】______the rate at which man discovered new knowledge. For example, prior to Gutenberg【C17】______11 chemical elements were known. Antimony(锑)the 12th, was discovered【C18】______about the time he was working on his invention. It was fully 200 years since the 11th, arsenic(砒霜), had been discovered.【C19】______the same rate of discovery continued, we would by now have added only two or throe additional elements to the periodic table since Gutenberg.【C20】______, in the 450 years after his time, certain people discovered some seventy additional elements. And since 1900 we have been isolating the remaining elements not at a rate of one every two centuries, but of one every three years.
【C1】
A．knowledge
B．rate
C．development
D．accumulation
第4题
第7题
A.undergoing
B.going on
C.ongoing
D.undergone
第8题
The following are true of a periodic inventory system except that______.
A．under a periodic inventory system, cost of goods sold and ending stock are determined at the end of the accounting period
B．a periodic inventory system is generally used when the stock consists of a large number of relatively low cost items
C．a periodic inventory system has the advantage of providing cost of goods sold and stock on hand at any time during the period
D．under a periodic inventory system, a physical stock count should be taken at least once in the accounting period, usually at the end of the accounting period
