posted by amy21 .
on a domestic gas cooker the temperture in the hottest part of the flame is about 2200k.if salty eater is spilled in the flame then it becomes yellow-orange.measurements with a spectrometer show the presence of an emission line at 589n.
1) the solar spectrum shows an absorption line at 589nm rather than an emission line. explain why the solar absorption line is darker than the background while the flame emission line is brighter.
There is sodium vapor in the sun and it absorbs the energy at 589 nm coming from the sun.(I assume you meant nm and not just n.) That's why you get an absorption line at 589 nm. There is no sodium vapor on earth (or at least very very little) AND you don't have a continuum as you have in the sun. So the emission line is all you see on earth. Look up atomic absorption spectrophotometry and see how we measure the amount of sodium in a sample BY ABSORPTION (when we pass sodium vapor from a flame emission THROUGH a sodium vapor lamp and let the lamp absorb the energy of emission.