ABSTRACT
Quantization of energy The term spectroscopy refers to an experimental subject that is concerned with the absorption, emission, or scattering of electromagnetic radiation. The earliest spectroscopic observations were made using the most accessible region of the electromagnetic spectrum; that is, visible light. In 1665 Newton started experiments on the dispersion of white light into a range of colors using a glass prism. Over two centuries later Balmer fitted the visible spectrum of atomic hydrogen to a mathematical formula. In doing so he showed that discrete wavelengths had to be considered. The classic Newtonian picture would require the spectrum to show a continuous change with wavelength and hence was at odds with the new observations. A detailed explanation of the hydrogen spectrum was not possible before the work of Planck at the start of the 20th century. He proposed
that tiny oscillators, atoms or molecules for example, have an oscillation frequency u, which is related to the energy of emitted radiation E by the expression;
E = nhu
where n is an integer and h is known as Planck’s constant.
