搜题请搜索小程序“爱下问搜题”
问题 推断题

现有部分短周期元素的性质或原子结构如下表

用化学符号回答以下问题：

（1）比较：氢化物的稳定性：T_________Z，最高价氧化物对应水化物的酸性：T________Y。（填“>”、“<”或“=”）

（2）Y元素位于元素周期表中第________周期，第_______族。请你设计一实验方案，证明X的氯化物是离子化合物还是共价化合物。简要写出实验内容、现象和结论。______________________。

（3）X的最高价氧化物对应水化物与烧碱反应的离子方程式为：________________________。

（4）T、X、Y、Z四种原子的半径由大到小的顺序为：_________________________。

答案

（1）<；> 

（2）3；IVA族；将氯化铝加热到熔融态，进行导电性实验，如果不导电，说明是共价化合物

（3）Al(OH)3+OH-=AlO2-+2H2O

（4）Al、Si、N、O

不定项选择 共用题干题

东方有限责任公司（以下简称东方公司）为增值税一般纳税人，2013年11月30日的科目余额表如下表所示：东方公司12月份有关资料如下：（1）本月销售商品售价50000元，增值税税额8500元，款项尚未收到。商品成本为42000元。（2）收回以前年度已核销的坏账140元。（3）向承包商支付工程款13000元。（4）计提本月固定资产折旧2500元，摊销长期待摊费用300元，均计入管理费用。另用银行存款支付其他管理费用4000元。（5）本月支付已预提的短期借款利息7840元。（6）用银行存款偿还短期借款11000元。（7）发生财务费用566元，均以银行存款支付。（8）年末按应收账款余额的4‰计提坏账准备。（9）出售交易性金融资产，出售时账面价值为15000元（其中：成本14000元，公允价值变动1000元），售价16000元。其他交易性金融资产年末公允价值未发生变动。要求：根据上述资料，不考虑其他因素，分析回答下列第（1）-（6）小题。（金额单位用元表示）

根据资料（1）至资料（3），下列说法或会计处理正确的是（）。

A.收回以前年度已核销的坏账不影响应收账款账面价值

B.资料（1）的会计分录：借：应收账款58500贷：主营业务收入50000应交税费-应交增值税（销项税额）8500借：主营业务成本42000贷：库存商品42000

C.资料（2）的会计分录：借：应收账款140贷：坏账准备140借：银行存款140贷：应收账款140

D.资料（3）的会计分录：借：在建工程13000贷：银行存款13000
查看答案
单项选择题 案例分析题

Today ,as in every other day of the year ,more than 3000 U.S. adlescents will smoke their first cigarette on their way to becoming regular smokers as adults. During their lifetime,it can be expected that of these 3000 about 23 will be murdered,30 will die in traffic accidents, and nearly 750 will be killed by a smoking-related disease. The number of deaths attributed to cigarette smoking outweithts all other factors, whether voluntary or involuntary, as a cause of death.

Since the late 1970s, when daily smoking among high school seniors reached 30 precent , smoking rates among youth have declined . While the decline is impressive ,several important issues must be raised.

First, in the past several years,smoking rates among youth have declined very little. Second,in the late 1970s ,smoking among male high school seniors exceeded that among female by nearly 10 percent . The statistic is reversing.Third ,several recent studies have indicate high school dropouts have excessively high smoking rates, as much as 75 percent .

Finally, thouth significant declines in adolescent smoking have occurred in the past decade,no definite reasons for the decline exist. Within this context,the Naional Cancer Instiute (NCI) began its current effort to determine the most effecive measures to reduce smoking levesl among youth.

The reason for declining adolescent smoking is that （）.

A.NCI has taken effective measures

B.smoking is prevented among high school seniors

C.there are many smokers who have died of cancer

D.none of these
查看答案