If the atom is emitting light then the spectral line is bright, if the atom is absorbing light the spectral line is dark, So emission spectra are bright.
Return to lower energy levels To be in the ground state all electrons must be in their lowest energy state; all excited atoms must lose energy. The lost energy appears in the form of light. Hope this...
Because, different elements react differently to heat. Elements produce different line spectra's because they are exposed to heat and they give off a colour or " line spectra".
All elements have their own discrete power spectra, to excite a hydrogen atom requires a different amount of energy than to excite a helium atom. The enery of a photon is proportional to its...