Henry Gwyn Jeffreys Moseley was an English Physicist who experimentally found out that the major properties of an element are found by the Atomic number and not by the atomic weight. He also firmly established the relationship between atomic number and the Charge of the atomic nucleus. Henry Moseley was educated at Trinity College, in Oxford. In 1910, at the age of 23, he was appointed lecturer in physics at Ernest Rutherford's laboratory. He studied under Rutherford until 1915 when he was drafted into World War I. He was killed in action at age of 27 at the Battle of Suvla Bay in turkey.
While Moseley was at the University of Muchester, he first concerned his research with radioactivity and beat radiation in radium. He then decided to jump to the study of the X-ray spectra of the elements. During his research he built on the work of many other great physicist, such as Sir William Bragg and his son Lawrence, who developed a method to reflect X-rays and measure their wavelengths by diffraction using crystals. Moseley used potassium ferrocyanide crystal to diffract X-rays produced by different metals and examine the spectra. He arranged his crystals to so he could control the angle between the crystal face and the X-ray beam. He reflected each element a set of angles and by measuring the angle he could find out the wavelength of the X-ray hitting the crystal. Finding this out he showed that every element has different frequencies that differ from change in mass of the atom. It was rather the change in charge on the nucleus. He called this the atomic num!
In 1913, he published his results of his experiments. The results showed that ordering the elements would be by atomic number and not atomic weight. When finally atoms were arranged according to atomic number, the problems of Mendeleev's periodic table had vanished.
Because of Henry Gwyn Jeffereys Moseley's work, our modern periodic table is based on the atomi...