A、B、C、D、E、F都是短周期元素,原子序数依次增大。 (1)D2C的电子式_

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问题:

A、B、C、D、E、F都是短周期元素,原子序数依次增大。

(1)D2C的电子式________________;

(2)沸点:A2C________A2E(填“>”或“<”或“=”)。

(3)E的非金属性比F_________(填“强”或“弱”),并用化学事实加以说明(用化学方程式表示)

__________________________

(4)化合物甲由A、B、C、D四种元素组成,其化学式量为84,是焙制糕点所用发酵粉的主要成分之一。写出甲在水溶液中与盐酸反应的离子方程式________________________                 

考点:元素的性质电子式的书写
题型:填空题

下列关于光现象的说法中,正确的是(  )

A.人远离平面镜,人在镜中的像大小不变

B.汽车在夜间行驶时,应打开驾驶室里的灯

C.阳光下,微风吹拂的河面波光粼粼,这是由于发生了光的反射现象

D.暗室里,为了能从镜子中看清自己的脸部,应当把手电筒正对着镜子照射

题型:填空题

指令寄存器的位数取决于( )。

A.存储器容量

B.机器字长

C.指令字长

D.指令字长和机器字长

题型:填空题

福利本质上是一种( )的社会关系。

A.国家间

B.公民间

C.公民与国家间

D.私人间

E.组织间

题型:填空题

各干线航空通运局每天的交航频次不低于()。

A.2次

B.3次

C.4次

D.5次

题型:填空题

Passage One

In many countries today, laws protect wildlife. In India the need for such protection was realized centuries ago.

About 300 B. C. an Indian writer described forests that were somewhat like national parks today. The killing of game animals was carefully governed. Some animals were fully protected. Within the forest, nobody was allowed to cut trees, burn wood, or trap animals for their furs. Animals that became dangerous to human visitors were trapped or killed outside the park, so that other animals would not become uneasy.

The need for wildlife protection is greater now than ever before. About a thousand sorts of animals are in danger of extinction, and the speed at which they are being destroyed has been putting on. With mammals, for example, the speed of extinction is now about one sort every year; from A. D. 1 to 1800, the speed was about one sort ever), fifty years. Everywhere, men are trying to solve the problem of saving wildlife while caring for the world’s growing population.

The word" extinetion"in this report most properly means“()”.

A.falling down

B.dying out

C.growing up

D.going away

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