At the quantum scale physics becomes hugely unpredictable and particles appear to defy the laws of physics at every turn, only obeying classical physics on 'average'. Beta rays appear to have wave like properties, they consist of electrons, which are known to have a mass and have particle like properties. So electrons are known as wavicles. I am trying to understand how electrons act when they orbit an atom, in particular how heat energy causes electrons to 'jump' to higher principle energy levels, become unstable, 'fall' back down and release EM radiation. How does the kinetic soup of vibrating atoms cause the electron to become displaced? Why does an electron 'jump' when only a certain amount of energy has been applied to it? My previous idea of an atom is a very small particle nucleus at the center with a large and rigid orbitting wall of electrons compared to the size of the nucleus. This idea of an atom obviously does not apply to the quantum world. I believe that to help understand how heat causes electrons to 'jump', I need to get a better idea of how electrons act at the quantum scale. What are the properties of electrons in orbit around an atom?