问题 选择题

下列叙述中,指定粒子的数目约为6.02×1023的是(    )

A.标准状况下,22.4 L H2和CO混合气体中的原子数

B.1.6 gCH4中含有的电子数

C.24 g金属镁与足量的盐酸反应转移的电子数

D.1 mol·L-1的稀硫酸100 mL中含有H+的数目

答案

答案:B

本题考查阿伏加德罗常数和粒子之间的关系。考查学生逻辑思维能力。

A项H2和CO都是双原子分子,所以应为2×6.02×1023,C应为2×6.02×1023,D应为0.2×6.02×1023

阅读理解

阅读理解。

     What are you going to do if you are in a burning house? How will you escape it? Do you know how to save

yourself? Please read the following passage.

     Escaping a fire is a serious matter. Knowing what to do during a fire can save a life. It is important to know

the way you can use and show them to everyone in the family, such as stairs and fire escapes, but not lifts.

     From the lower floors of the building, escape through windows is possible. Learn the best way of leaving

by windows with the least chance of serious injury (伤). The second floor window is usually not very high from

the ground. Maybe it is safer to jump a short way than to stay in a burning building.

     Windows are also useful when you are waiting for help. Be sure to keep the door closed before opening the

window. Or smoke and fire may be drawn (吸) into the room. Keep your head low at the window to be sure

you get fresh air.

     On a second or third floor, the best windows for escape are these which open onto a roof. From the roof a

person can drop to the ground more safely. Bushes (灌木丛) and grass can help to break a fall.

1. The passage tells us how to escape from _____.

A. a fire

B. an earthquake (地震)

C. a flood

2. The second floor window is usually not very high from ______.

A. the house

B. the ground

C. the wall

3. You can't escape through ______ if you are in a burning house.

A. stairs

B. lifts

C. fire escapes

4. ______ to be sure you get fresh air when you are waiting for help in a burning house.

A. Keep your head low at the window

B. Keep your head high at the window

C. Keep the door open

5. According to the passage, which of the following is NOT true?

A. Escaping a fire is a serious matter.

B. Windows are also useful when you are waiting for help.

C. Bushes and grass can't help to break a fall.

判断题