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Topic: Calculating energy level from wavelength  (Read 3188 times)

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Offline funstrike123

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Calculating energy level from wavelength
« on: November 17, 2014, 11:01:38 AM »
The transition of an electron from a higher level to a lower level results in the emission of a photon of wavelength 350.0 nm. If the energy of the higher level is -3.24 x 10^-19 J, calculate the energy of the lower level.

By using E = hv

I find E = 5.679 x 10^-28 J

How do I use this value to solve the qus?

Offline Corribus

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Re: Calculating energy level from wavelength
« Reply #1 on: November 17, 2014, 11:17:07 AM »
What's the relationship between the frequency and wavelength of light?

EDIT: Sorry, I should have paid more attention. I see you already figured that much out.

The transition energy is given by

ΔE = E(upper) - E(lower)

If you know what the upper energy level is, and you know what the transition energy ΔE is, then the energy of the lower energy state is easily determined by subtracting the one from the other.
« Last Edit: November 17, 2014, 11:28:09 AM by Corribus »
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Offline funstrike123

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Re: Calculating energy level from wavelength
« Reply #2 on: November 17, 2014, 11:26:48 AM »
What's the relationship between the frequency and wavelength of light?

speed of light = wavelength x frequency?

I used that to find E = 5.679 x 10^-28 J

Is this the answer already? omg I'm confused

Offline Corribus

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Re: Calculating energy level from wavelength
« Reply #3 on: November 17, 2014, 11:27:43 AM »
Sorry, I didn't read your first post well enough. Please see my edit above. But do be careful with your units.
What men are poets who can speak of Jupiter if he were like a man, but if he is an immense spinning sphere of methane and ammonia must be silent?  - Richard P. Feynman

Offline funstrike123

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Re: Calculating energy level from wavelength
« Reply #4 on: November 17, 2014, 11:45:18 AM »
Sorry, I didn't read your first post well enough. Please see my edit above. But do be careful with your units.

Thanks for your hint! I spent hours figuring out why my value is so small.
1nm = 10^-9 m. I see why now.

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