题目内容
氢原子处于基态时,原子能量E1= -13.6eV,已知电子电量e =1.6×10-19C,电子质量m=0.91×10-30kg,氢的核外电子的第一条可能轨道的半径为r1=0.53×10-10m.
(1)若要使处于n=2的氢原子电离,至少要用频率多大的电磁波照射氢原子?
(2)氢原子核外电子的绕核运动可等效为一环形电流,则氢原子处于n=2的定态时,核外电子运动的等效电流多大?
(3)若已知钠的极限频率为6.00×1014Hz,今用一群处于n=4的激发态的氢原子发射的光谱照射钠,试通过计算说明有几条谱线可使钠发生光电效应?
(1)若要使处于n=2的氢原子电离,至少要用频率多大的电磁波照射氢原子?
(2)氢原子核外电子的绕核运动可等效为一环形电流,则氢原子处于n=2的定态时,核外电子运动的等效电流多大?
(3)若已知钠的极限频率为6.00×1014Hz,今用一群处于n=4的激发态的氢原子发射的光谱照射钠,试通过计算说明有几条谱线可使钠发生光电效应?
(1)
Hz
(2)
A
(3)有
、
、
、
四条谱线可使钠发生光电效应
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122152489400.gif)
(2)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122152504351.gif)
(3)有
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122152676233.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122152692233.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122152707234.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122152723238.gif)
(1)要使处于n=2的氢原子电离,照射光光子的能量应能使电子从第2能级跃迁到无限远处,最小频率的电磁波的光子能量应为:![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122152754585.gif)
得
Hz,
(2)氢原子核外电子绕核做匀速圆周运动,库伦力作向心力,有
①
其中![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122152848372.gif)
根据电流强度的定义
②
由①②得
③
将数据代入③得
A
(3)由于钠的极限频率为6.00×1014Hz,则使钠发生光电效应的光子的能量至少为
eV="2.486" eV
一群处于n=4的激发态的氢原子发射的光子,要使钠发生光电效应,应使跃迁时两能级的差
,所以在六条光谱线中有
、
、
、
四条谱线可使钠发生光电效应。
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122152754585.gif)
得
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122152489400.gif)
(2)氢原子核外电子绕核做匀速圆周运动,库伦力作向心力,有
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122152832640.gif)
其中
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122152848372.gif)
根据电流强度的定义
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122152894283.gif)
由①②得
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122152910709.gif)
将数据代入③得
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122152504351.gif)
(3)由于钠的极限频率为6.00×1014Hz,则使钠发生光电效应的光子的能量至少为
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241221530821069.gif)
一群处于n=4的激发态的氢原子发射的光子,要使钠发生光电效应,应使跃迁时两能级的差
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122153097419.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122152676233.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122152692233.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122152707234.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122152723238.gif)
![](http://thumb2018.1010pic.com/images/loading.gif)
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