什麼電子躍遷吸收和釋放的大部分能量?

2010-02-02 9:19 pm

What electronic transitions absorbs and emits the most energy?
(1) n =1 to n = 3
(2) n =3 to n = 4
(3) n =3 to n = 2
(4) n =5 to n = 3

which absorbs the most energy and why?
which emits the most energy and why?

回答 (1)

天同

2010-02-03 4:41 am

✔ 最佳答案

Energy absorbed by electron transition in Event (1) is larger than that in Event (2).

Since energy E of electron in an orbit of principal quantum number n is given by,

E = -k/n^2
where k is a constant
Transition in Event (1) abosrbs an amount of energy
= k[1/1^2 - 1/3^2] = 8k/9 units

Transition in Event (2) absorbs energy of
= k[1/3^2 - 1/4^2] = 7k/144 units
Clearly, Event (1) absorbs larger energy than Event (2)

Likewise, when electron transits from a higher level to a lower level, energy is released.
The energy given out in Event (3) = k(1/2^2 - 1/3^2) = 5k/36 units
The energy given out in Event (4) = k(1/3^2 - 1/5^2) = 16k/225 units

Hence, Event (3) emits larger energy.

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