The classical theory of physics predicts that the shorter than wavelength of EMR absorbed, the more intense the radiation released. However this meant that it would violate the conservation of energy as the area under a black body curve would be infinite. The black body that was produced with experimental data showed that the curve peaked at UV instead of going off to infinity at short wavelengths, as classical physics predicted. The experimental black body curve could not be produced with classical physics mathematics.
Planck proposed that black body radiation was quantised to solve this problem. Although this assumption produced a mathematical formula that could perfectly explain experimental data, he was sceptical of it being true. Whilst classical theory states that EMR can have any range of frequencies or energies, Planck's new quantum theory stated that black body EMR has energy that is an integral multiple of its frequency. His proposal, whilst controversial, was successful in explaining the nature of the black body curve and solved the UV catastrophe that classical physics could not, and is therefore the theory that is used today.
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Outline the method used by the Braggs to determine crystal structure 3 MARKS
p.s. can someone tell me if my answers are ok