Final answer:
Air is normally an insulator but can become a conductor under certain conditions like high pressure, temperature, or ionization, which can occur in events like thunderstorms and create plasma.
Step-by-step explanation:
If the particles in the air were close enough to test, whether air would conduct electricity depends on several factors. Normally, air is an insulator, meaning it does not conduct electricity well. However, under certain conditions such as high pressure or temperature, or if the air particles are ionized, air can become a conductor. When the air particles are forced closer together, or if there are enough free electrons, the likelihood of air conducting electricity increases. For instance, when there is a high-voltage difference, like during a thunderstorm, the air can become ionized, forming plasma, and a lightning bolt can occur, which is a visible form of electrical conduction through the air.