ISCI 2002 Lecture Notes - Lecture 1: Ernest Rutherford, Bohr Model, Principal Quantum Number
Document Summary
Chapter 9: modern physics (after 1900, dealing with electrons in the atom, classical physics (before 1900) deals with large-scale things. Early concepts of the atom: thought matter was continuous (could be divided infinitely) instead of discrete until 1807. Showed evidence that matter was discrete and existed as particles. Each element is composed of small indivisible particles called atoms. J. j. thompson (1903: plum pudding model . Rays were deflected by electric and magnetic fields. Electrons stuck randomly in homogenous mass of positively charged pudding . Ernest rutherford (1911: 99. 97% of mass is the nucleus, electrons circulating around positive core. Electron cloud model (today: cloud density reflects probability that the electron is in that region. Concepts of quantized energy: 4 specific potential energy values, quantized energy. Each orbit is characterized by a quantum number. Only change in energy when moving into another orbit.
