You might have seen those bright colorful neon lights shining everywhere. They attract people's eye toward shops, bars, cafes and a lot of places after sunset. Many business people are happily gaining the attention of their potential customers these days with these inexpensive neon lights.
We might be clued-up about the uses and benefits of these affordable decorative lights and sign boards but here is a little about the workings of them. The atoms of rare gasses like helium, neon and argon don't form stable molecules by means of chemical bonding with the other atoms.
If you are looking for a reason as to why neon is not inert in a discharge tube, it is quite easier to explain it than the process of elaboration of why it is inert to the chemical reactions. The voltage that is passed through the discharge tube will be accelerating a free electron by boosting up its energy level to some maximum kinetic energy.
If you had been ever thinking of how these gasses emit light, then here you have the answer for it. As an option to having been detached or removed by an energetic collision what happens is the electron inside an atom will get excited to a level and start moving with high-speed.