Ionisation of air is a phenomenon that occurs when air is exposed to a direct or indirect energy flow, such as solar radiation, flames, radioactive sources or strong electric fields. This behaviour is a useful basis for understanding spark meters, Geiger-Müller tubes and fog chambers, and is also a step towards constructing a model of atoms. The luminescent emission of the characteristic blue-purple-violet light, often referred to as electric blue, is produced when air is ionised. When energy is deposited in the air, the molecules become excited.
As air is mainly composed of nitrogen and oxygen, excited N2 and O2 molecules are formed. These can react with other molecules, primarily forming ozone and nitrogen (II) oxide. Water vapour, when present, can also contribute; its presence is characterised by hydrogen emission lines. The reactive species present in the plasma can easily interact with other chemicals present in the air or on nearby surfaces. The observed blue light is mainly generated by this process.
The spectrum is dominated by monoionised nitrogen lines, with the presence of neutral nitrogen lines. This reaction is responsible for the production of ozone in the vicinity of highly radioactive materials and electrical discharges. In dry air, the colour of the light produced (for example, by lightning) is dominated by nitrogen emission lines, resulting in a spectrum with mainly blue emission lines. The lines of neutral nitrogen (NI), neutral oxygen (OI), individually ionised nitrogen (NII) and individually ionised oxygen (OII) are the most prominent features of the emission spectrum of a ray. Neutral nitrogen radiates mainly in a line in the red part of the spectrum. Ionised nitrogen radiates mainly as a set of lines in the blue part of the spectrum. The ionisation process has many applications in science and technology.
It can be used to measure radiation levels with spark meters and Geiger-Müller tubes, as well as to create fog chambers for studying aerosols. It also helps us to understand how atoms work and how they interact with each other. The ionisation process can be used to create ozone in areas where there are high levels of radiation or electrical discharges. This ozone can help to purify the air and reduce pollution levels.
It can also be used to create hydrogen fuel cells for clean energy production. In conclusion, ionisation of air occurs when energy is deposited into it, resulting in excited molecules that react with other molecules to form ozone and nitrogen (II) oxide. This process produces a characteristic blue-purple-violet light that has many applications in science and technology.
