One hundred years ago this week, a Danish physicist (and former footballer), Neils Bohr, wrote a letter to his mentor (the famed physicist Ernest Rutherford) in which he described a new model for the make-up of the atom. It brought the new science of quantum mechanics into the equation and was the first step in revealing the atom to be far weirder than anyone had ever imagined...
THE STORY OF THE ATOM begins in the 5th century BC in Ancient Greece. A chiton-clad thinker called Democritus formulated the idea that matter might be comprised of tiny particles that were ‘atomos’, or indivisible. These ‘atoms’ couldn’t be broken up as there was nothing smaller for them to be broken into.
Then, for more than 2,000 years, not a lot happened in the world of atomic science. Finally, in the early 19th century, an English physicist and chemist called John Dalton formulated his own ‘atomic theory’.
Dalton’s atom was much the same as the ancient Greeks’ but he went on to suggest the different elements were made of atoms of different sizes and that the elements could be combined to create more complex compounds. He was also the first person to make a serious attempt to calculate the atomic mass of some of the chemical elements and to introduce a system of chemical symbols.