ATOMS — Physics STD 12 Science — Question

→Every substance (solid, liquid and gas) emits electromagnetic radiation at every temperature. This radiation contains many different wavelengths. Among these, some wave lengths are continuously distributed but their intensity varies.
→This radiation arises due to the oscillations of atoms and molecules.
→By heating or exciting a gas of sufficiently low density, the light emitted from it contains only a few discrete or specific wave lengths. This spectrum appear as a series of light.
→Gases with sufficiently low density have more space between atoms. Hence the emitted radiation can be assumed to be due to individual atoms rather than interactions between molecules or atoms.
→Each element is associated with a characteristic spectrum of radiation. For example, hydrogen always gives a set of lines with fixed relative position between the lines. Means they are at certain fixed locations.
→This fact shows that there is a close relationship between the internal structure of an atom and the spectrum of radiation emitted by it.