Question

Lines of a particular element appear at the same wavelength in both emission and absorption line spectraTrue or False

Answer 1

Answer: True

Each atom emits or absors electromagnetic radiation, but only in some frequencies that are characteristic of its chemical element.

Now, if we supply energy in the form of heat (thermal energy) to a certain element in its gas phase, this will be stimulated  and its atoms will emit radiation in certain frequencies of the visible spectrum, which constitute its emission spectrum.

If the same element, also in gaseous state, receives electromagnetic radiation, it absorbs in certain frequencies of the visible spectrum, precisely the same ones in which it emits when it is stimulated by heat. This will be its absorption spectrum.

This means that every element absorbs radiation in the same wavelengths in which it emits it.