Bohr Model

whiteshado

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______

quasar987

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

[tex]E=hf[/tex]

where f is the frequency of the photon. How are frequency and wavelenght related?

whiteshado

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?

what

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.

whiteshado

well speed of sound divided by wavelength =frequency

whiteshado

is taht what you were asking for?

whozum

A photon travels at the speed of _____

whiteshado

hf is the energy of the radiated photons

thats all i got

whozum

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.

quasar987

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.

whiteshado

k so correct me if im wrong 2-1 =-13.6 evs and w =-13.6evs/6.63e-34

?

quasar987

-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:

[tex]\Delta E = E_f - E_i[/tex]

whiteshado

12.2? is that it? nope it was 10.2

quasar987

yeah.

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whiteshado

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?

quasar987

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.

whiteshado

ahhh i devided instead of multiplying