问题 填空题

在真空中,氢原子从能级A跃迁到能级B时,辐射出波长为λ1的光子;从能级A跃迁到能级C时,辐射出波长为λ2的光子.若λ1>λ2,真空中的光速为c,则氢原子从能级B跃迁到能级C时将________光子(填“吸收”或“辐射”),其光子的波长为________.

答案

辐射 λ1λ2/(λ1-λ2)

分析:明确原子能级跃迁过程中产生或吸收光子能量与光子波长、频率之间关系.原子从高能级向基态跃迁放出能量,反之吸收能量.比较能级高低能级间能量关系列式求解.

解答:解:原子从A能级状态跃迁到B能级状态时发射波长为λ1的光子;原子从A能级状态跃迁到C能级状态时辐射波长为λ2的光子,已知λ1>λ2

故:BC能级之间能量等于AB能级与AC能级之间能量之差,即有:,故从A能级状态跃迁到C能级状态时将要吸收波长为:λ31λ2/(λ1-λ2)

故答案为:辐射;λ1λ2/(λ1-λ2)

点评:明确原子能级跃迁过程中产生或吸收光子能量与光子波长、频率之间关系,列式求解即可.

阅读理解

阅读理解。

     My sister Alli and I have been trying to get people to stop dropping cigarette butts (烟蒂) for seven years.

     One day, we were walking in our hometown and saw hundreds of cigarette butts on the ground.

     They made the ground dirty.

     They made the town look so ugly that we decided to start a group to make people stop dropping butts.

We called it "No Butts About It!" At first, we drew pictures with "The Earth Is Not Your Ashtray (烟灰缸)"

written on them. We put the pictures around our hometown-in parks, by beaches, and along roads.

     We wanted to make people understand that dropping butts does harm to the environment. Most smokers

don't think that dropping butts harms the earth. But it does! All rubbish does.

     Later, we wrote to companies and asked them for money to help us. We used the money to buy ashtrays

to give smokers.

     We wanted smokers to carry the ashtrays with them so they didn't have to drop butts. At the moment, we

are trying to get cigarette companies to put an ashtray in each pack of cigarettes. Some companies would like

to do it.

     Many people have started to join our group since it began. Today there are 45 other "No Butts About It"

groups in America. And there are even groups in England, Australia and India!

     Many newspapers have written about my sister and I over the last seven years. And we have won many

prizes for our good work.

    But we are not interested in prizes. We just want to make the earth a better and cleaner place for animals,

plants and people.

     One day it will be.

根据短文内容, 完成下列各题.

1. It has _____ Alli and the writer seven years to try to _____ people stop dropping cigarette butts.

2. The cigarette butts made the town look so _____ that they decided to start a group _____"No Butts

    About It."

3. First, they drew pictures and put them around their hometown. Then they _____ to companies to

    ask for money. _____ the money they buy ashtrays to give smokers.

4. There are many" No Butts About It" groups in _____, _____, Australia and India.

5. They hope that one day the earth will be a _____ and _____ place for animals and people.

解答题