问题 选择题

短周期A、B、C三种元素原子序数依次递增,它们的原子最外层电子数之和为11,A、C同主族,B原子最外层电子数比A原子次外层电子数多1.下列叙述正确的是(  )

A.B的氧化物熔点比A的氧化物低

B.原子半径:B>C>A

C.B的最高价氧化物的水化物只是一种碱

D.由A、B两元素分别形成的单质均存在同素异形体

答案

短周期A、B、C三种元素原子序数依次递增,它们的原子最外层电子数之和为11,A、C同主族,设A的最外层电子数为x,则C的最外层电子数为x,B原子最外层电子数比A原子次外层电子数多1,则A的次外层为2,即B的最外层电子数为3,所以x+x+3=11,解得x=4,即A为C,B为Al,C为Si,

A.氧化铝为离子晶体,二氧化碳为分子晶体,则氧化铝的熔点高,故A错误;

B.电子层越多,半径越大,同周期从左向右原子半径在减小,则原子半径为B>C>A,故B正确;

C.B的最高价氧化物的水化物为氢氧化铝,属于两性氢氧化物,故C错误;

D.A元素存在同素异形体,如金刚石、石墨,而B不存在同素异形体,故D错误;

故选B.

单项选择题
问答题

James Shapiro follows his award-winning book on William Shakespeare, 1599, which came out in 2005, with an unlikely subject: an investigation into the old chestnut that Shakespeare wasn’t the man who wrote the works.

Most mainstream Shakespeareans stand aloof from it. But apparently the claims of Francis Bacon, Edward de Vere and Christopher Marlowe, among others, are on the rise. (46) An appetite for conspiracy theories, combined with a call for "balance" from some sectors of academe and the rise of the Internet has given the thing new life. Respectable audiences turn up to listen to lectures on it. The controversy is even taught at university level. "What difference does it make who wrote the plays" someone asked the author wearily. Mr. Shapiro (for whom Shakespeare was definitely the man) thinks it matters a lot, and by the end of this book, his readers will think so too.

The authorship controversy turns on two things., snobbery and the assumption that, in a literal way, you are what you write. How could an untutored, untravelled glover’s son from hickville, the argument goes, understand kings and courtiers, affairs of state, philosophy, law, music-let alone the noble art of falconry (47) Worse still, how could the business-minded, property-owning, moneylending materialist that emerges from the documentary scraps, be the same man as the poet of the plays

Mr. Shapiro teases out the cuhural prejudices, the historical blind spots, and above all the anachronism inherent in these questions. No one before the late 18th century had ever asked them, or thought to read the plays or sonnets for biographical insights. No one had even bothered to work out a chronology for them. (48) The idea that works of literature hold personal clues, or that--more grandly--writing is an expression and exploration of the self, is a relatively recent phenomenon.

Contested Will is dense with lives and stories and argument. It is also entertaining. The quest for the true claimant drove people mad. (49) Here are secrets and codes, an elaborate cipher-breaking machine, an obsession with graves and crazy adventures to find lost manuscripts. One man spent months dredging the River Severn. Mr. Shapiro himself turns sleuth, exposing as fraudulent a piece of evidence long thought to be genuine-one more hoax in the long history of Shakespearean wild goose chases.

(50) The Shakespeare that emerges is both simple and mysterious: a man of the theatre, who read, observed, listened and remembered. Beyond that is imagination, In essence, that’s what the book is about.

(47) Worse still, how could the business-minded, property-owning, moneylending materialist that emerges from the documentary scraps, be the same man as the poet of the plays