Reinventing the Table

　　An earth scientist has rejigged（调整） the periodic table （元素周期表）to make chemistry simpler to teach to students.

　　_____（1）____ But Bruce Railsback from the University of Georgia 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（交叉） his hands in the air and pointing to different bits of a traditional table.___（2）_____ But he has added contour lines to charge density， helping to explain which ions（离子） react with which.

　　Geochemists just want an intuitive sense of what's going on with the elements，“ saysAlbert Galy from the University of Cambridge ____（3）____

　　___（4）___ He explains that sulphur（硫磺）， for example， shows up in three differentspots __one for sulphide（硫化物）， which is found in minerals， one for sulphite（亚硫酸盐）， 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.___ （5）___

　　练习：

　　A There have been many attempts to redesign the periodic table since Dmitri Mendeleevit up in 1871.

　　B Railsback has still ordered the elements ac， cording 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.

　　练习答案

　　1A 2B 3C 4D 5E