Ion Channels: Structure and Function. Ion channels are membrane protein complexes and their function is to facilitate the diffusion of ions across biological membranes. Membranes, or phospholipid bilayers, build a hydrophobic, low dielectric barrier to hydrophilic and charged molecules. They are electrical insulators.
The inert gas xenon (chemical symbol Xe) has an atomic number of 54, and it has 54 protons in its nucleus. The number of neutrons varies, however.
Xenon is a trace gas found in the Earth's atmosphere to the extent of about one part in 20 million, According to the Los Alamos National Laboratory. This makes it very rare. It is also found in Mars' atmosphere at 0.08 ppm. This noble gas can also be found down on Earth.