Question

Which of the following solids is not an electrical conductor?
(I) $M{{g}_{(s)}}$
(II) $Ti{{O}_{(s)}}$
(III) ${{I}_{2(s)}}$
(IV) ${{H}_{2}}{{O}_{(s)}}$
A. (I) only
B. (II) only
C. (III) and (IV)
D. (II), (III) and (IV)

Answer 1

Hint: A conductor is a device that comprises electrical charges that are movable. The passing charged particles are electrons in metallic conductors such as copper or aluminum. Insulators are non-conductive materials with few mobile charges; only small electrical currents are borne by them.

Complete step by step answer:
 Conductors are the materials or substances which allow electricity to flow through them. They conduct electricity because they allow electrons to flow easily inside them from atom to atom. Also, conductors allow the transmission of heat or light from one source to another.
Metals, humans, earth and animals all are conductors. This is the reason we get electric shocks. Moreover, the human body is a good conductor. So, it provides a resistance-free path for the current to flow from wire to body. Conductors have free electrons on its surface which allow current to pass through easily. This is the reason why conductors are able to conduct electricity.
(I) $M{{g}_{(s)}}$
$M{{g}_{(s)}}$ is metallic solid and is a conductor in solid as well as in molten state.
(II) $Ti{{O}_{(s)}}$: $Ti{{O}_{(s)}}$ is an ionic solid and is an insulator in solid state but is a conductor in molten state and in aqueous solutions.
(III) ${{I}_{2(s)}}$: ${{I}_{2(s)}}$ is a non-polar molecular solid and it is an insulator. Hence, does not conduct electricity.
(IV) ${{H}_{2}}{{O}_{(s)}}$: ${{H}_{2}}{{O}_{(s)}}$ is a hydrogen bonded molecular solid and it is also an insulator. Hence, does not conduct electricity.
Hence, $Ti{{O}_{(s)}}$, ${{I}_{2(s)}}$ and ${{H}_{2}}{{O}_{(s)}}$ are insulators, they do not conduct electricity. Thus, they are not electrical conductors.
So, the correct answer is “Option D”.

Note: Always remember, $Ti{{O}_{(s)}}$ is an ionic solid and is an insulator in solid state but is a conductor in molten state and in aqueous solutions.
Insulators are the materials or substances which resist or don’t allow the current to flow through them.
Wood, cloth, glass, mica and quartz are some good examples of insulators.