Question

Air is a/an ____ conductor of electricity.
A. good
B. poor
C. extremely good
D. neutral

Answer 1

Hint: Air is a mixture of gases which either are inert or poor conductors of electricity.
Among metals, silver is the best conductor of electricity, and then copper, gold and aluminum respectively. Liquids also conduct electricity, but conductions occurs due to movement of ions.

Complete step by step answer:
Electric current is the rate of flow of electrons per unit time.
For conduction of current, free electrons or ions are essential. The conductivity of a substance increases with increase in ion concentration.
In an atom of a substance, the electrons in the orbits close to the nucleus are bound to it under the strong attraction of the nuclear positive charge, but electrons far from the nucleus experience a very feeble force. Hence, the outer electrons can be removed easily. In fact, the outer electrons leave their atoms and move freely within the substance. These electrons are called free electrons. In metals, the number of free electrons is quite very large. Hence, metals are good conductors of electricity.
In gases, electric conduction occurs by the movements of both positive and negative charge-carriers, ions.
Air is a mixture of neutral or inert gases. Therefore it contains few or no charged particles or free ions for conduction of electricity. Hence, air is a poor conductor of electricity.

So, the correct answer is “Option B”.

Note:
 Nitrogen gas, the most abundant gas in air is a poor conductor of electricity. Inert gases, such as neon, have complete valence shells and so have no free electrons, hence are poor electrical conductors.