Which substance(s) will be good conductors of electricity?

Question

I. H2O (s)
II. NaCl (s)
III. NaCl (l)
IV. Au (s)
Responses
A I and II onlyI and II only
B III and IV onlyIII and IV only
C II and IIIII and III
D All of them

Answer 1

To determine which substances are good conductors of electricity, we need to consider their states and compositions.

1. H2O (s): Ice (solid water) does not conduct electricity well because it does not have free-moving ions or electrons.

2. NaCl (s): Solid sodium chloride (table salt) does not conduct electricity because its ions are fixed in a lattice structure and cannot move freely.

3. NaCl (l): Liquid sodium chloride, when dissolved in water or melted, allows the sodium and chloride ions to move freely, making it a good conductor of electricity.

4. Au (s): Solid gold is an excellent conductor of electricity due to the free movement of electrons in the metal.

Based on this analysis, the substances that are good conductors of electricity are:

• III. NaCl (l)
• IV. Au (s)

Therefore, the correct response based on the provided options is:

B: III and IV only.