The motion of ion charges in a liquid or gas is called:

The correct answer is option 4):(Ionization current)

Concept:

• Ionization current is an electric current produced in an ionized gas subjected to an electric field
• The motion of ion charges in a liquid or gas is called Ionization current
• An ion is an atom or group of atoms in which the number of electrons is different from the number of protons.

Additional Information

• The phenomenon of ionisation of surrounding air around the conductor due to which luminous glow with hissing noise is rise is known as the corona effect. 
• During the passage of electric current, the holes will move in the opposite direction of electrons it is said to be hole flow
• Superconductivity is defined as the ability of certain materials to conduct electricity without loss of energy at a low temperature called Critical temperature.