## Frequency if energy goes from n=2 to n=4

H-Atom ($E_{n}=-\frac{hR}{n^{2}}$)

LilianKhosravi_1H
Posts: 32
Joined: Fri Apr 06, 2018 11:03 am

### Frequency if energy goes from n=2 to n=4

So today in lecture we talked about how when the electron goes from n=4 to n=2 the change in energy would be negative and so in return the energy of the photon emitted is positive so in return the frequency is positive. But, if the electron goes from n=2 to n=4 then the change in energy will be positive so will the energy of the photon being emitted be negative? If so then would the frequency be negative?

tatianatumbling_1J
Posts: 31
Joined: Mon Jan 08, 2018 8:19 am

### Re: Frequency if energy goes from n=2 to n=4

I had the same question! But I do remember him saying that the energy of a photon can only be positive. But I don't know how that works out.

SammiOrsini_1B
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Joined: Fri Apr 06, 2018 11:04 am

### Re: Frequency if energy goes from n=2 to n=4

im not sure if i have this right, but if we know when we go down in energy levels a photon is emitted, if we go up in energy levels would something be absorbed or nothing be emitted at all?

Alicia Yu 1A
Posts: 30
Joined: Thu Feb 22, 2018 3:02 am

### Re: Frequency if energy goes from n=2 to n=4

The higher the energy of a photon absorbed, the higher the energy level it jumps to. Energy of a photon can not be negative.

Chem_Mod
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### Re: Frequency if energy goes from n=2 to n=4

Sammi is correct. For an electron to go up energy levels, energy is required. Thus a photon of light would be absorbed instead of emitted, but the frequency of the light will always be positive.

Salena Chowdri 1I
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Joined: Fri Apr 06, 2018 11:02 am

### Re: Frequency if energy goes from n=2 to n=4

When you go from a lower energy level to a higher level, energy is require. The electron absorbs this energy, over releasing a photon. So as mentioned, photons will not have a negative value of energy. However, the change in energy of the electron will be positive going up energy levels and negative coming down.

Gabi Landes 1-H
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Joined: Thu Feb 22, 2018 3:00 am

### Re: Frequency if energy goes from n=2 to n=4

When moving up energy levels light is absorbed & not emitted -- however ^^^ they are right, it cannot be negative!