Andra found these notes in her notebook: 1. in 1897, j. j. thomas discovered electrons. 2. in 1913, niels bohr found evidence that electrons are arranged in energy levels. 3. in 1926, erwin schrödinger’s work led to the electron cloud model. her notes refer to some of the discoveries that led to the development of the atomic law. when schrödinger’s electron law became a theory. when schrödinger’s electron hypothesis became a law. some of the discoveries that led to the development of the atomic theory.