<p>Can you explain steps by steps with an answer?
THx</p>
<p>An excited hydrogen atom emits light with a frequency of 1.145 1014 Hz to reach the energy level for which n = 4. In what principal quantum level did the electron begin?</p>
<p>bumppppppppppppppppppp</p>
<p>Wait, are you saying it emits a frequency of 1014 or 1.145?
The equation for a quantum or energy in a photon is :
E=h(planck's constant)v(frequency of the wavelength)
but then I'm not exactly sure what you are asking. Is n=4 the orbital level?</p>
<p>I guess you will have to use Rydberg equation E=Rh(1/ni^2 - 1/nf ^2) to find the initial level of energy. You got E (from Plank's equation E=hv), Rh, nf (nf= final level of energy=4) so you got one variable to solve for (ni=initial level of energy)
I haven't taken chem II or Physics II so take my equations with a grain of salt.</p>
<p>Sorry, I didn't notice you wanted step by step answers.</p>
<p>E=hv; h= Plank's constant= 6.626(10^-34)
E= 6.626(10^-34)<em>(1.145</em>10^14)=7.58677^-20</p>
<p>Rh=1.097<em>10^7, nf=4, ni=?, E= 7.58677</em>10^-20
E=Rh(1/ni^2 - 1/nf ^2)
E+Rh/nf^2=Rh/ni^2
ni=(Rh/(E+Rh/nf^2))^.5</p>
<p>I'm growing sleepy. Hope this helps.</p>
<p>hmm. Okay. Althought I didn't ask the question,this is helping me as well. ^-^. I'm just on that chapter about electromagnetic radiation and such.</p>