CBSE Class 11-science Answered

An element's 'emission spectrum' is the relative intensity of electromagnetic radiation of each frequency it emits when it is heated (or more generally when it is excited).When the electrons in the element are excited, they jump to higher energy orbits. As the electrons fall back down, and leave the excited state, energy is re-emitted, the wavelength of which refers to the discrete lines of the emission spectrum.

An absorption spectrum occurs when light passes through a cold, dilute gas and atoms in the gas absorb at characteristic frequencies; since the re-emitted light is unlikely to be emitted in the same direction as the absorbed photon, this gives rise to dark lines (absence of light) in the spectrum