# Bohr Model

Tags: bohr, model
 P: 33 could i get help or a formula for this question please Use the Energy Levels for Hydrogen to calculate the wavelength corresponding to the following electron transition Transition Energy in ev's Emitted wavelengths in m 2->1______ ________x10______
 Sci Advisor HW Helper PF Gold P: 4,771 Here's a formula you can use after you've discovered how many energy is contained in the photon emited during the transition of the electron $$E=hf$$ where f is the frequency of the photon. How are frequency and wavelenght related?
 P: 33 taht is the question im as stumped as you are tahts all the info i have i had taht equation though it doesnt haev wavelength also how do i find the energy?
 P: 91 Bohr Model I dont think quasar is stumped, i think he was asking you a question which has an answer. The energy should be a given, or predicted by the bohr model. Think back to waves what other equation relates wavelength and frequency.
 P: 33 well speed of sound divided by wavelength =frequency
 P: 33 is taht what you were asking for?
 P: 2,218 A photon travels at the speed of _____
 P: 33 hf is the energy of the radiated photons thats all i got
 P: 2,218 Ok, a photon travels at the speed of light. If its energy is given by hF, then the relationship c = (Frequency)(Wavelength) should give you its wavelength. All you ahve to do is find the energy drop from 2->1 and solve this equation and plug it into the E = hF one.
HW Helper
PF Gold
P: 4,771
 Quote by whiteshado well speed of sound divided by wavelength =frequency
This is also true for light. Light is a wave too, and a "photon" is only a fancy name we give to "little chuncks" (quanta!) of light.

So speed of light divided by wavelength =frequency.
 P: 33 k so correct me if im wrong 2-1 =-13.6 evs and w =-13.6evs/6.63e-34 ?
HW Helper
PF Gold
P: 4,771
 Quote by whiteshado k so correct me if im wrong 2-1 =-13.6 evs and w =-13.6evs/6.63e-34 ?
-13.6 eV is the energy the electron has when it is in state n=1.

You're looking for the energy it has lost in going from state n=2 to state n=1, hence you want the difference between the energy of n=1 and the energy of n=2:

$$\Delta E = E_f - E_i$$
 P: 33 12.2? is that it? nope it was 10.2
 Sci Advisor HW Helper PF Gold P: 4,771 yeah. -----------
 P: 33 hmm i got 1.15e53 10.2/1.6e-19/6.63e-34 its not right thought i think i missed soemthing wait is this is my freqwuancy correcT?
 Sci Advisor HW Helper PF Gold P: 4,771 1 kg = 1000 grams, so 2.3 kg = 2.3*1000 = 2300 grams. Same thing here: 1 eV = 1.6*10^19 J, so 12.2 eV = 12.2*1.6*10^-19 J.
 P: 33 ahhh i devided instead of multiplying
 Mentor P: 11,876 In problems like this it's easier to use Planck's constant in eV instead of joules: $$\frac {10.2 eV} {4.14 \times 10^{-15} eV \cdot seconds}$$

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