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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: schrodingersdog on October 19, 2019, 02:27:49 AM

Title: What's the difference between E=nhv and E=hv (Midterm on Monday)
Post by: schrodingersdog on October 19, 2019, 02:27:49 AM

I recently did a problem on this, and used E=nhv but it gave off a wrong answer. When I checked the answer, they used E=hv. However, the question gave me n, so why can't I use the first formula?
Btw, this is the question:
An excited hydrogen atom emits light with a wavelength of 397.2 nm to reach the energy level for which n = 2. In which principal quantum level did the electron begin?

Thanks for taking the time to read this, my Midterm starts on Monday so I would appreciate it if someone could help me out asap  ;D

Title: Re: What's the difference between E=nhv and E=hv (Midterm on Monday)
Post by: Corribus on October 19, 2019, 11:46:03 AM

Have you learned the Rydberg formula?

Title: Re: What's the difference between E=nhv and E=hv (Midterm on Monday)
Post by: schrodingersdog on October 20, 2019, 12:16:19 AM

Yes

Title: Re: What's the difference between E=nhv and E=hv (Midterm on Monday)
Post by: Corribus on October 20, 2019, 01:37:38 AM

Well then that is the formula you should be using along with the n value given,  to determine the unknown n value.

Title: Re: What's the difference between E=nhv and E=hv (Midterm on Monday)
Post by: Enthalpy on October 21, 2019, 02:21:55 PM

n is a number of photons in nhν. Elsewhere, it is an energy level.

Title: Re: What's the difference between E=nhv and E=hv (Midterm on Monday)
Post by: schrodingersdog on November 04, 2019, 05:21:48 PM

Oh ok I got it! Thanks