Question 8
In the conductivity test, the bulb did not light in the beaker of distilled water. What does this show?
The right answer is the one marked above.
Water is covalent, so it provides no free ions. Water molecules are whole and uncharged, and a current has nothing to move through them.
This is why the test uses distilled water rather than tap water — tap water carries dissolved ionic salts, which would conduct and spoil the comparison. Temperature is not the issue, and the bulb worked in beakers A and B.