Modern Atomic Model

According to the modern atomic model,
  1. The central nucleus consists of protons and neutrons. It containing almost all the mass of the atom.
  2. the nucleus of an atom is very small compared to the size of the atom
  3. the electrons are orbiting outside the nucleus in the electron shells
  4. the electrons are moving in electron shells at a very high speed and we cannot determine the position of the electrons at a particular time