The Science Behind Neon Lights: A Simple Explanation
According to the definition, the atoms in gas molecules that are inert like neon, helium, or argon will never (well, rarely) form stable molecules by chemically bonding with other molecules. It is easy to make an inert gas discharge tube like a neon lamp. This suggests that inertness may be relative. It is all you need to do is apply the smallest amount of electric current to the electrodes on the end of a glass tube filled with the inert gas, and the light begins to glow.
It’s much easier to explain why neon doesn’t change into inert during a discharge tube rather than explain why it turns inert in chemical reactions. A discharge tube can increase the speed of a free electron up to a certain energy kinetic. The voltage has to be big enough to ensure that the energy is more than that required to “ionize” the atom. A positively charged ion is an element that has been ionized. It means that it has been able to take an electron from an orbital to make it “free” of a particle. The electric current between the electrodes of the tube tubes is transported by the plasma of charged electrons and ions.
Photo ( above) illustrates the gas discharge sign Sam Sampere, Syracuse University created by Sam Sampere, Syracuse University. The sign features a neon discharge tube (the “Physics” word in orange) and mercury discharge tubes (the “Experience” or the “Experience” word in blue) and an outer frame. The lower part of the custom neon sign is a representation of the electric and magnetic fields of light. The yellow and white sine waves of the sculpture are fluorescent light sources. They are mercury discharge tubes equipped with special coatings on their walls. The coating absorbs light from the mercury discharge within the tube and releases light that is lower in energy (and it is a different color) Depending on the exact material of the coating, an array of colors is possible.
What is the reason why the gas discharges emit light? Electrons can be stimulated so that they can be removed from an atom. The electron is thought to be elevated to an orbital that has higher energy. When the electron eases back to its initial orbital the light particle (a photon) removes the energy generated by excitation and the discharge tube glows! A photon’s energy (its wavelength or color) is determined by the energy difference between orbitals. A given atom can emit photons with different energies, which correspond to the different pairs of orbitals. The photon energy spectrum is the emission lines to spectroscopists unique to a particular atom. As you can see in the picture, mercury discharge tubes display a very different hue than neon discharge tubes. This is how Helium, the inert gas, was discovered. The observations of sunlight revealed several photon energy levels that had never been seen before in Earth discharges.
The chemical inertness of some gases is more difficult to explain. When two atoms are nearby and have the highest energy or valence, the orbitals of the atoms shift dramatically and the electrons on the two atoms shift. Chemical bonds can form when this reorganization decreases the energy of electrons in total. For ordinary, non-inert atoms, the electrons are relatively malleable and bonds can form. The electrons of inert gas are, however, insensitive to the proximity effect and, therefore, they rarely form bonds to make molecules.
An example of an even larger phenomenon is the unbearable inertness of matter. This paradox is caused by the inertness (about chemical bonding) of a gas, and its dynamism in a glow discharge. A particle can be described as an inert, non-reactive particle when the energy involved in its interaction is small enough to keep electrons from being excited. The atoms of inert gasses like neon are among the most laid back. However, interactions increase and nuclei are unable to maintain their integrity. We end up with an amalgamation of electrons as well as inert nuclei. This is a highly charged plasma. The energy can be increased and the nuclei become less inert. We are instead served a mixture of nucleons in a neutron star. It is possible to increase the energy even more and enter the world of quarks. Even nucleons can no longer be inert, and we’re back to the primordial, energetic conditions that were present shortly after the big bang.