Medical Definition of PNEUMOTAXIC CENTER. : a neural center in the upper part of the pons that provides inhibitory impulses on inspiration and thereby prevents overdistension of the lungs and helps to maintain alternately recurrent inspiration and expiration. a neural center in the upper part of the pons that provides inhibitory impulses on inspiration and thereby prevents overdistension of the lungs and helps to maintain alternately recurrent inspiration and expiration.
Because of their uber-high stability, the noble gases are relatively unreactive. They have very high ionization energies and negligible electronegativities because they have no desire to gain or lose an electron.
Noble gases are stable because they have a complete outer shell-that is, eight valence electrons. Other elements react in order to gain or lose valence electrons, but noble â¦ gases are satisfied.oble gases have completely filled orbitals / energy levels. They generally have 8 valence electrons (helium has only 2 valence electrons) and have stable electronic configura â¦ tion. Hence they are chemically inert and generally donot form compounds under normal conditions.