Erwin Schrödinger (1887 - 1961)

 

Developed a probability function that describes a cloud-like region where the electron is likely to be found. Its a mathematical equation of wave mechanics. He improved Bohrs claim because he said that electrons are located in a cloud-like region where they move around freely. 

His model was called the cloud model. It was called the cloud model because it is a cloud-like region that indicates where an electron can most likely be found.