Which of the following is best conductor of electricity ?

Options

A. Sea water
B. Rain water
C. Ordinary water
D. Distilled water

Explanation

**Step-by-Step Solution:**

1. **Understanding Conductivity in Water**:
- The ability of water to conduct electricity depends on the presence of ions. Ions are charged particles that can move freely in water and carry electric current.

2. **Analyzing Seawater**:
- Seawater contains dissolved salts such as sodium chloride (NaCl) and magnesium chloride (MgCl). These salts dissociate into ions (Na⁺, Cl⁻, Mg²⁺, etc.) when dissolved in water.
- The presence of these free ions makes seawater a very good conductor of electricity.

3. **Analyzing Rainwater**:
- Rainwater is generally pure but may contain trace amounts of dissolved gases and minerals. However, it has significantly fewer ions compared to seawater.
- As a result, rainwater has lower conductivity than seawater.

4. **Analyzing Ordinary Water**:
- Ordinary water (tap water) may contain some dissolved minerals and impurities, which can provide some ions. However, its conductivity is still lower than that of seawater.

5. **Analyzing Distilled Water**:
- Distilled water is purified water that has had most of its impurities and ions removed.
- Because it lacks free ions, distilled water is a poor conductor of electricity.

6. **Conclusion**:
- Comparing the conductivity of seawater, rainwater, ordinary water, and distilled water, seawater has the highest concentration of ions and thus is the best conductor of electricity.

**Final Answer**: The best conductor of electricity among the options provided is **seawater**.

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