Who is a Jew? familiar with and willing to vouch for the Jewishness of their maternal lineage or the validity of their conversion. There have been several attempts to convene representatives of the three major movements to formulate a practical solution to this issue. To date, these have failed, though all parties concede the importance of the issue is greater than any sense of rivalry among them. Ethnic Jew is a term generally used to describe a person of Jewish parentage and background who does not necessarily actively practice Judaism, but still identifies with Judaism or other Jews culturally or fraternally, or both. The
Quantum chemistry particles, which later came to be called photons (1926). In the years to follow, this theoretical basis slowly began to be applied to chemical structure, reactivity, and bonding. Probably the greatest contribution to the field was made by Linus Pauling. The first step in solving a quantum chemical problem is usually solving the Schrödinger equation (or Dirac equation in relativistic quantum chemistry) with the electronic molecular Hamiltonian. This is called determining the electronic structure of the molecule. It can be said that the electronic structure of a molecule or crystal implies essentially its chemical properties. An exact solution for the