neons absorbtion spectrum?

Question

Imagine the TWO following situations. 1) Pass an electrical current through a diffuse neon vapour, and observe neon's emission spectrum. 2) Pass the light from a glowing, white-hot iron bar through a relatively cool, diffuse neon vapour, and observe neon's absorption spectrum.

Which of the following statements is true?


1)The wavelengths of the dark lines in the absorption spectrum are exactly the same as the wavelengths of some of the coloured lines in the emission spectrum.
2) The product of the object's temperature (in kelvins) and the longest wavelength in the emission spectrum is 2.9 x 10(to the negative 3) kelvin-meters.
3)The product of the object's temperature (in kelvins) and the longest wavelength in the absorption spectrum is 2.9 x 10(to the negative 3) kelvin-meters.
4)There are more lines in the absorption spectrum than there are in the emission spectrum.
5)The reason that there are more lines in the emission spectrum than in the absorption spectrum is that a magnetic field "splits" each absoprtion line into three emission lines.

Answer 1

1. True



2. True



Explanation



Wavelength of max emission of sun (um) = 0.48 um (um is micron = 0.000001meter)

Temperature of the sun is 6000k

Wavelength of max emission x temperature = 6000x 0.48 x 0.000001 =2.88 x 10 -3





3. Not true



Explanation



Sun's longest wavelength in absorption spectrum = 2.2 um ( micron)

Sun's temp is 6000k

Sun's longest wavelength x temperature is 6000 x 2.2 x 0.000001 = 0.0132 kelvin – meter





4. Not true



Explanation



There are fewer spectral lines in absorption than in the emission spectrum.



Let's take sodium as an example to answer this.

In the case of emission spectra the missing wavelengths are not absorbed by sodium vapour and in the case of absorption spectra, the missing wavelengths are absorbed the sodium vapour because the light of these wavelengths is exactly of the right energy to cause electron transitions within the sodium atoms.This is why, there is fewer spectral lines in absorbtion than in emmision spectrum





5. True (The Zeeman Effect)



Explanation



Take the sodium atom. Its absorption spectrum has 3 lines while emission spectrum has 9 lines.





Source : Mc-grawhill encyclopedia / various

Answer 2

1

Answer 3

all the spectra are led to while an electron "jumps" from one potential point to a distinctive. The absorption is led to via elevating the electron to a miles better point, and the emission is led to if the electron falls returned to its unique point. by using fact an analogous potential ranges are all in touch in the two circumstances, an analogous spectrum could additionally be in touch. i.e no count number if it incredibly is attainable to develop an electron from point 2 to point 5 ( absorption) it would be attainable for an electron to fall from point 5 to point 2 (emission)