如图所示，大量氢原子处于能级n=4的激发态，当它们向较低能级跃_爱下问搜题

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问题选择题

如图所示，大量氢原子处于能级n=4的激发态，当它们向较低能级跃迁时，对于多种可能的跃迁，下面说法中正确的是（　　）

A．从n=4能级跃迁到n=2能级放出的光子的频率等于从n=2能级跃迁到n=1能级放出的光子的频率

B．最多只能放出3种不同频率的光子

C．从n=4能级跃迁到n=1能级放出的光子频率最高

D．从n=4能级跃迁到n=1能级放出的光子波长最长

答案

A、n=4和n=2间的能级差小于n=2和n=1间的能级差，则从n=4能级跃迁到n=2能级放出的光子的频率小于从n=2能级跃迁到n=1能级放出的光子的频率．故A错误．

B、根据数学组合公式C

24

=6知，处于n=4激发态，最多能放出6种不同频率的光子．故B错误；

C、n=4能级跃迁到n=1能级，能极差最大，辐射光子频率最高，波长最小．故C正确，D错误；

故选：C．

完形填空

阅读下面短文，掌握其大意，然后从41─60各题所给的四个选项（A、B、C和D）中选出最佳选项，并在答题卡上将该项涂黑。
“Father, I don’t like to go to school,” said Harry Williams one morning. “I wish you would let me stay at home. Charles Parker’s father doesn’t make him go to school.”
Mr Williams 36 his little boy by the hand, and said   37  to him, “Come, my son. I want to show you 38  in the garden.”
Harry walked into the garden with his   39 , who led him along until they came to a bed in which peas(豌豆) were growing. Not a weed(杂草) was to be 40  about their roots.
“See how beautifully these peas are   41, my son,” said Mr. Williams. “How clean and healthy the vines(藤) look. We shall have a good   42 . Now let me show you the vines in Mr. Parker’s garden.”
Mr. Williams then 43 Harry to look at Mr. Parker’s pea vines.
After a few moments, Mr. Williams asked, “Well, my son, what do you   44 Mr. Parker’s pea vines?”
“Oh, Father!” replied the little boy. “I never saw such 45 looking peas in my life! The weeds are nearly as 46 as the peas themselves. There won’t be half a crop!”
“ 47  are they so much worse than ours, Harry?”
“Because they have been left to grow as they 48 . I suppose Mr. Parker just planted them, and never took any care of them 49 ”
“ Yes. A garden will soon be overrun with weeds 50  it is not taken good care of,” Mr. Williams 51 , “and so it is with the human garden. Children’s minds are like garden beds. They must be 52  cared for. I send you to school in order that the garden of your 53  may have good seeds(种子) and   54 plentifully. Now which would you 55 , to stay at home or go to school?”
“I would rather go to school,” said Harry.

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单项选择题

在以下哪一种母版中插入徽标可以使其在每张幻灯片上的位置自动保持相同？（）

A.讲义母版。

B.幻灯片母版。

C.标题母版。

D.备注母版。