Bromine is a chemical element with the symbol Br and atomic number 35. It is the third-lightest halogen, and is a fuming red-brown liquid at room temperature that evaporates readily to form a similarly coloured vapour. Its properties are intermediate between those of chlorine and iodine. Isolated independently by two chemists, Carl Jacob Löwig (in 1825) and Antoine Jérôme Balard (in 1826), its name was derived from the Ancient Greek βρῶμος ("stench"), referring to its sharp and disagreeable smell.
Before the advent of the wave-particle duality theory proposed by Louis de Broglie, there was a sharp distinction between mater and waves.
However, Louis de Broglie introduced the idea that mater could display wave-like properties. Erwin Schrödinger developed this idea into what is now known as the wave mechanical model of the atom.
In this model, electrons are regarded as waves. We can only determine the probability of finding the electron within certain high probability regions within the atom called orbitals.
This idea has been the longest surviving atomic model and has greatly increased our understanding of atoms.
