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.
What are the properties of noble gases? Noble gases are the quiet ones, they are the least reactive on the  periodic table. Noble gases have completely filled orbitals /  energy levels. They generally have 8 valenâ¦ce electrons (helium has  only 2 valence electrons). Helium and neon have filled valence  shells. The noble gases have high ionization energies and stable  electronic configuration, so they have little tendency to gain or  lose electrons. Hence they are chemically inert and generally do  not form compounds under normal conditions.