(10分)A、B、C、D、E原子序数依次递增的五种短周期元素,已知: ①B原子核

题型:填空题

问题:

(10分)A、B、C、D、E原子序数依次递增的五种短周期元素,已知:

①B原子核外电子总数与最外层电子数之比为4:3

②D原子最外层电子数与次外层电子数之比为3:4

③E-,C+,A+的离子半径逐渐减小

④A单质在E单质中燃烧火焰呈苍白色

请回答下列问题:

(1)E的最高价氧化物对应水化物的化学式为:___________。它的酸性比D的最高价氧化物对应水化物的酸性:____________。(填“强”或“弱”)

(2)X、Y是由上述元素中任意3种组成的强电解质,且构成的原子个数比均为1:1:1。已知X溶液中水电离出来的C(H+)=10-12mol/L,则X的电子式为:_____________;Y的水溶液酸碱性与X相同,则其原因是(写离子方程式):_______________________________;

(3)B与C构成原子个数比为1:1的化合物与H2O反应的化学方程式为:__________________________________________;

(4)A与B,A与D均可形成18个电子的分子,这两种分子在水溶液中反应生成物之一是含10电子的化合物;该反应可观察到现象是:____________________________________,原因是(用化学方程式表示)_______________________________________________。

考点:构成物质的粒子—分子、原子、离子元素周期律
题型:填空题

股份制不是公有制经济的实现形式。 ( )

题型:填空题

细胞过行分裂,产生的新细胞和原细胞所含有的遗传物质是不一样的。[ ]

题型:填空题

Kofi Annan says helping survivors of last week’ s earthquake and (1) in the Indian Ocean is (2) . The United Nations secretary- general says countries that have offered aid must (3) and provide it. The offers add up to around (4) dollars. United Nations officials say (5) of that is needed during the next six months. The concern about offers of international aid is (6) . For example, the earthquake in Barn, Iran, in (7) of 2003 killed more than (8) people. Countries and groups offered hundreds of millions of dollars (9) .The United Nations says it has (10) only about (11) dollars in aid received so far. Governments and organizations that offered help (12) that, however. On (13) Mr. Annan met with world leaders in Jakarta, Indonesia to discuss aid for (14) . The leaders discussed and (15) the idea of (16) owed by affected nations. But the leaders did not say they would do so. Some said that (17) to survivors would be more helpful. Representatives of (18) countries and international organizations attended the meeting in Jakarta. Officials say they will cooperate to develop (19) for the Indian Ocean and the (20) .

题型:填空题

预制构件的吊环,必须采用未经冷拉的( )级钢筋制作,严禁以其他钢筋代换。

A.HPBl35

B.HPB235

C.HRB435

D.HRB335

题型:填空题

Java提供的类库支持下列哪个协议,使应用程序可通过URL地址,在网络上的任何地方访问对象时,就跟本机一样

A.2

B.3

C.4

D.5

更多题库