What is a photon? How is the energy of a photon related to its wavelength? Its frequency?
Solution Step 1 (a) (i)Henry Mosley through his x ray experiment found a property which would help to position the elements in the periodic table. The concept of atomic number became more meaningful through his experiments.In his experiment he used an electron gun to fire a stream of electrons (like machine gun bullets) at samples of different elements. He found that the elements gave off X-rays.Moseley measured the frequency of the X-rays given off by different elements.By taking the square root of the frequency, Moseley found that the increase was constant from one element to the next. Each element gave a different frequency and he found that this frequency was mathematically related to the position of the element in the Periodic Table.Thus he was able to measure the atomic number of elements. (ii)These X rays came from positively carged particles in the nucleus called protons. Step 2 Moseley plotted the square root of the X-ray frequency against atomic number