问题 选择题

下列说法正确的是(NA表示阿伏加德罗常数)(     )

A.在常温常压下,11.2 L N2含有的分子数为0.5 NA

B.在常温常压下,1mol He含有的原子数为2 NA

C.71g Cl2所含原子数为2 NA

D.23g Na在化学反应中失去的电子数目为10 NA

答案

答案:C

题目分析:A.在常温常压下,11.2 L N2不一定为0.5mol,所以含有的分子数不一定为0.5 NA,A错误。

B.He为单原子分子。在常温常压下,1mol He含有的原子数为NA,B错误。

C.71g Cl2为1mol 所含原子数为2 NA,正确

D.钠原子在反应时失去1个电子,23g Na在化学反应中失去的电子数目为 NA,D错误。

点评:本题考查了阿伏伽德罗常数的有关计算,难度不大,易错选项是B,注意氦是单原子分子。

阅读理解

阅读理解。正确的写“T”,错误的写“F”。

      A woman saw three old men sitting in her front yard. She said, "I don't think I know you, but you

 must be very hungry. Please come in and have something to eat."

     "We don't go into a house together," they replied.

     "Why is that?" she asked.

     One of the old men answered. "His name is Wealth, this is Success, and I am Love." Then he said,

 "Now go in and discuss with your family which one of us you want in your house."

     Then the woman went in and told her family what was said. She said "Let's invite Wealth. Let him come

  in and bring us nice things. We have been so poor. "His husband disagreed, "My dear why don't we invite

 Success? Don't you want me to be a successful man?" Then the daughter asked, "Would it be better to

 invite Love? Our life will then be filled with 1ove!" "Let's take our daughter's advice (建议),"said the

 father and mother.

     So the woman went out and asked, "Which one of you is Love? Please come in and be our guest.

 "Love got up and started walking toward the house.The other two also got up and followed him.

 Surprised, the lady asked Wealth and Success, "I only invited Love. Why are you corning along? " The

  two o1d men answered, "If you had invited Wealth or Success, two of us would have stayed out,but

 since you have invited Love, wherever he goes, we go with him. Where there is Love. there is Wealth and

  Success."

1. This is a true story that happened a long time ago.

2. Wealth could make the family very rich.

3. The family had different ideas and didn't know whom to invite.

4. The three old men all went into the house to get something to eat.

5. The story tells us that 1ove is the most important of all.

填空题