Can it be explained via blackbody radiation? Or is it purely to do with the material itself? For example, why does the line at 589.0 nm has twice the intensity of the line at 589.6 nm for sodium?

Desirae Washington
2022-07-13
Answered

Can it be explained via blackbody radiation? Or is it purely to do with the material itself? For example, why does the line at 589.0 nm has twice the intensity of the line at 589.6 nm for sodium?

You can still ask an expert for help

haingear8v

Answered 2022-07-14
Author has **13** answers

Sodium is not a blackbody. Rather the spectrum is determined by all the possible transitions between energy levels of it's electrons. Some of those levels are degenerate to varying degrees. If there are a lot of possible transitions with the same energy, the spectrum of the material will have a higher intensity for those energies, or wavelengths, respectively.

DIAMMIBENVERMk1

Answered 2022-07-15
Author has **2** answers

These two examples are of different origins.

The black body spectrum is the results of two factors: Bloltzmann distribuition ${e}^{-\beta \hslash \omega}$ and the available number of modes between $\nu $ and $\nu +d\nu $, $N(\nu )$. The intensity of spectrum of frequency $\nu $,

$I(\nu )=N(\nu )\sum _{j=1}^{\mathrm{\infty}}j{e}^{-j\beta h\nu}=\frac{N(\nu )}{{e}^{\beta h\nu}-1}\propto \frac{{\nu}^{3}}{{e}^{\beta h\nu}-1}$

The different intensity of Na (589 nm) and (589.6 nm) is due to the state multiplicity ${P}^{2/3}$ and ${P}^{1/2}$. The degeneracy is equal to $g(j)=2j+1$. For $j=\frac{3}{2}$ degeneracy $g(\frac{3}{2})=4$, while $j=\frac{1}{2}$ degeneracy $g(\frac{1}{2})=2$. The degeneracy ratio $g(\frac{3}{2}):g(\frac{1}{2})=2:1$

The black body spectrum is the results of two factors: Bloltzmann distribuition ${e}^{-\beta \hslash \omega}$ and the available number of modes between $\nu $ and $\nu +d\nu $, $N(\nu )$. The intensity of spectrum of frequency $\nu $,

$I(\nu )=N(\nu )\sum _{j=1}^{\mathrm{\infty}}j{e}^{-j\beta h\nu}=\frac{N(\nu )}{{e}^{\beta h\nu}-1}\propto \frac{{\nu}^{3}}{{e}^{\beta h\nu}-1}$

The different intensity of Na (589 nm) and (589.6 nm) is due to the state multiplicity ${P}^{2/3}$ and ${P}^{1/2}$. The degeneracy is equal to $g(j)=2j+1$. For $j=\frac{3}{2}$ degeneracy $g(\frac{3}{2})=4$, while $j=\frac{1}{2}$ degeneracy $g(\frac{1}{2})=2$. The degeneracy ratio $g(\frac{3}{2}):g(\frac{1}{2})=2:1$

asked 2022-05-14

Why can one observe an electronic transition of the 3s state to the 3p state in the emission spectrum of the nitrogen atom, but not in its absorption spectrum?

I know that the selection rules technically don't forbid either one since $\mathrm{\Delta}\ell =\pm 1$ is permitted.

I know that the selection rules technically don't forbid either one since $\mathrm{\Delta}\ell =\pm 1$ is permitted.

asked 2022-05-17

If the average number of photons emitted by an oscillatory pattern from the surface of a black object is (28-10.2) photon at room temperature.Calculate the following:

1. frequency of patterns emitted by this body.

2. wavelength associated with this emission.

3. within what range of the electromagnetic spectrum is this emission located

1. frequency of patterns emitted by this body.

2. wavelength associated with this emission.

3. within what range of the electromagnetic spectrum is this emission located

asked 2022-05-18

If a black body is radiating at ${17}^{\circ}$ C. Calculate the (a) wave length at which maximum energy will be radiated and (b) energy per unit area per second radiated by this black body.

asked 2022-05-17

Consider a large number of hydrogen atoms, with electrons all initially in the n = 4 state. (a) How many different wavelengths would be observed in the emission spectrum of these atoms? (b) What is the longest wavelength that could be observed? (c) To which series does the wavelength found in (b) belong?

asked 2022-08-07

The wavelengths of the visible spectrum are approximately 400nm (violet) to 700nm (red). Find the angular width of the first-order visible spectrum produced by a transmission diffraction grating with 405 lines per millimeter when white light falls normally on the grating. Give the answer in degrees.

asked 2022-05-17

What lines would be missing for hydrogen in an absorption spectrum? What wavelengths are missing for hydrogen in an emission spectrum?

asked 2022-07-19

Excitation of vibrational motion of molecules is associated with which region of the electromagnetic spectrum?

Group of answer choices

a)X-ray

b)infrared

c)microwave

d)visible

e)ultraviolet

Group of answer choices

a)X-ray

b)infrared

c)microwave

d)visible

e)ultraviolet