which of the following solids is not an electrical conductor ?
(a) Mg(s) (b) TiO(s) ( c) `I_(2)(s)` (d) `H_(2)O(s)`

Options

A. only 1
B. only 2
C. 3 and 4
D. 2,3 and 4

Explanation

To determine which of the following solids is not an electrical conductor, we will analyze each option provided:

**Question:** Which of the following solids is not an electrical conductor?
(a) Mg(s)
(b) TiO(s)
(c) I₂(s)
(d) H₂O(s)

### Step-by-Step Solution:

1. **Analyze Option (a) Mg(s):**
- Magnesium (Mg) is a metal. Metals are known for their ability to conduct electricity due to the presence of free-moving delocalized electrons in metallic bonding.
- **Conclusion:** Mg is a good conductor of electricity.

2. **Analyze Option (b) TiO(s):**
- Titanium oxide (TiO) is a compound that can conduct electricity in its solid state due to the presence of mobile charged particles (electrons) when subjected to a potential difference.
- **Conclusion:** TiO is a good conductor of electricity.

3. **Analyze Option (c) I₂(s):**
- Iodine (I₂) is a molecular solid. It consists of non-polar molecules held together by weak London dispersion forces. These molecules do not have free-moving charged particles, which means they cannot conduct electricity.
- **Conclusion:** I₂ is not a conductor of electricity.

4. **Analyze Option (d) H₂O(s):**
- Ice (solid water, H₂O) is a molecular solid with hydrogen bonds between the molecules. While water can conduct electricity when in liquid form due to the presence of ions, solid ice does not have free-moving charged particles and thus does not conduct electricity.
- **Conclusion:** H₂O is also not a conductor of electricity in its solid state.

5. **Final Decision:**
- Both I₂ and H₂O are non-conductors in their solid states. However, the question asks for the solid that is not an electrical conductor, and since I₂ is a pure molecular solid with no ionic character, it is the most straightforward answer.
- **Correct Answer:** (c) I₂(s)