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### Postive or Negative Frequency

Posted: Mon Oct 14, 2019 4:11 pm
Question on the Atomic Spectra Module asks: Calculate the frequency of a photon emitted by a hydrogen atom when an electron makes a transition from the fourth to the second principal quantum level.

I did the calculations and got
A. -6.17 x 10^14 Hz

However, it said my answer was wrong. Are frequencies suppose to be positive or was my math incorrect?

B. 1.62 x 10^-15 Hz

C. 6.17 x 10^14 Hz

D. 2.71 x 10^-52 Hz

### Re: Postive or Negative Frequency

Posted: Mon Oct 14, 2019 4:26 pm
Your math was correct but the answer is C because, although energy can be expressed as a negative value for energy lost, when calculating things such as frequency or wavelength, you always use positive values since there is no such thing as a negative frequency, for example.

### Re: Postive or Negative Frequency

Posted: Mon Oct 14, 2019 4:32 pm
Emily Vainberg 1L wrote:Question on the Atomic Spectra Module asks: Calculate the frequency of a photon emitted by a hydrogen atom when an electron makes a transition from the fourth to the second principal quantum level.

I did the calculations and got
A. -6.17 x 10^14 Hz

However, it said my answer was wrong. Are frequencies suppose to be positive or was my math incorrect?