“…We have more than 10 25 particles per cm 3 in the centre where T > 10 7 K, and less dense plasmas in the outer regions with T ∼ 10 4 K. For a crude approach, we may model the sun as a spherical plasma with (90-93)% mole fraction hydrogen and (6-8)% mole fraction helium and <2% heavier nuclei.The light elements, which are dominant in the sun, have lowest lying bound states, hydrogen atoms, hydrogen molecules, helium atoms, and helium ions, consisting of two to four charged particles. Our method [4] based on the relation between the so-called chemical picture and physical picture is heavily using this fact. In each case, the outer electrons are only loosely bound with ionization energies of I (1) H = 13.59 eV for atomic hydrogen, I (1) He = 24.56 eV for helium.…”