it comes from a hot, tenuous gas
"Emission Spectrum" can mean a number of things... Many objects emit light and they all have an emission spectrum, that is a set of wavelengths of light that they give out. The emission spectrum for an L.E.D. bulb for instance is pretty narrow, just one visible colour. The emission spectrum of a star is very wide, encompassing non-visible light as well. It is probably these stellar emission spectra you are referring to, so I'll go on from that assumption. The fusion processes within a star (at most levels from core to surface, but mostly in the core) create most of a spectrum, but some of this light is absorbed by the outermost layers. That is why we see gaps, and molecules of certain types absorb certain parts of the spectrum, so we use the spectrum to determine composition. We also see spectra from diffuse bodies like nebulae. These are, broadly, of 2 types, emission and absorption. Absorption spectra occur when we observe a known star through the cloud, and extra lines missing beyond what we expect of the star will be emblematic of the constituents of the cloud. Emission spectra from clouds can also occur, that is when the light falling on them is not aligned with us, what we see is several narrow bands of light, which has been absorbed and re-emitted by the cloud.
All hot solids or dense enough gases emit black body radiation. Gases that are not very dense are are cold absorb particular wavelengths while gases that are not dense but are hot produce their characteristic emission spectrum.
Because hydrogen is the most common element in the universe and also it has a spectral emission line in the microwave radio part of the spectrum making it easier to track with a radio telescope.
The cavity radiation spectrum comes from surface temperature. Bright line (emission) spectra come from hot elements near the surface. Dark line (absorption) spectra come from cooler elements further out. Because they're at different temperatures and have slightly different elemental ratios, each star produces a unique "fingerprint".
Yes, the political 3G Spectrum in India is in fact a scam. As is the 2G scam in India. Both are not to be trusted.
No. Atomic emission spectrum is non-contiuous and it is named as line spectrum.
To identify an unknown sample by its emission spectrum
absorption spectrum
No. It is not possible for two metals to have the same emission spectrum. For metals to have the same emission spectrum, they would need for their electrons to have duplicate orbitals. That would be impossible due to the exclusion principle.
The difference between continuous spectrum and the atomic emission espectrum of an element is that in emission spectrum, only certain specific frequencies of light are emitted while in a continuous spectrum, a continuous range of colors are seen in the visible light.
Identify elements
An emission spectrum depend on electrons transition in the atom of a chemical element; and elements are different.Absorption spectrum is based on the different absorption pics of different molecules, depending on the frequency of radiation.Spectral methods are largely used in analytical chemistry.
Red, blue, green, and violet are found in the emission spectrum of hydrogen.
because the emission wavelengths of mercury are very precisely known.
Every element can produce an emission spectrum, if it is sufficiently heated. Of the 4 elements that you mention, neon is the most useful, in terms of its emission spectrum, and it is used in a certain type of lighting.
Emission spectrum: lines emitted from an atom.Absorption spectrum: absorbed wavelengths of a molecule.
The emission spectrum can be used to determine the composition of a material