Question

Which one of the following is a bad conductor of electricity
${\text{A}}{\text{. }}$ Acid
${\text{B}}{\text{.}}$ Coal
${\text{C}}{\text{.}}$ Distilled water
${\text{D}}{\text{.}}$ Human body

Answer 1

- Hint: To check bad conductors of electricity we have to understand that when a material has fee ions or we may say electrons then it will be a good conductor of electricity. So here we have to check which material has free electrons and which has not.

Complete step-by-step solution -
Now we have option A.
Acid : as we know acid is those which gives ${H}^{+}$ ions so it will conduct electricity because it has free electrons. So option A is wrong.
In the second option we have coal and we know graphite is a form of coal which conducts electricity because carbon has four valence electrons in which only three take part in bond formation so one electron remains which carries electricity so coal is a good conductor of electricity.
Here in option c we have distilled water if we assume it pure water then it is bad conductor of electricity because it has no free electrons
Hence option C is the correct option .
Here in option D we have a human body in which body cells contain various ions like sodium ion, potassium ion, chloride ion etc. which have the tendency to conduct electricity and this makes our body a good conductor of electricity.
So option D is the wrong option .

Note: Whenever we get this type of question the key concept of solving it first we have to understand the meaning of good conductor and bad conductor and also have knowledge of all the terms used in the option then we will be able to answer this type of question.