The salts of which among the pairs of metals cause greater water pollution?

Options

A. Calcium, aluminium
B. Mercury, cadmium
C. Calcium, cadmium
D. Calcium, mercury

Explanation

To determine which pairs of metals cause greater water pollution, we can analyze the options provided and assess the impact of each metal on water quality.

### Step-by-Step Solution:

1. **Identify the Metals in Each Pair**:
- We need to look at the pairs of metals given in the options. For example, we might have pairs like Calcium (Ca) and Aluminum (Al), Mercury (Hg) and Cadmium (Cd), etc.

2. **Research the Environmental Impact of Each Metal**:
- **Calcium (Ca)**: Generally, calcium salts do not significantly pollute water. They are often found in natural water sources and are essential for aquatic life.
- **Aluminum (Al)**: Aluminum can cause some pollution, but it is less toxic compared to heavy metals.
- **Mercury (Hg)**: Mercury is highly toxic and is known to cause severe water pollution. It can accumulate in the food chain and have detrimental effects on aquatic life and human health.
- **Cadmium (Cd)**: Cadmium is also a heavy metal that is highly toxic and can cause significant water pollution.

3. **Evaluate Each Pair**:
- **Pair 1 (Calcium and Aluminum)**: Neither of these metals is a significant pollutant.
- **Pair 2 (Mercury and Cadmium)**: Both metals are known for causing severe water pollution.
- **Pair 3 (Calcium and Cadmium)**: Calcium is not a pollutant, but Cadmium is.
- **Pair 4 (Calcium and Mercury)**: Similar to the previous pair, Calcium is not a pollutant, but Mercury is.

4. **Determine the Most Polluting Pair**:
- From the evaluation, Pair 2 (Mercury and Cadmium) stands out as both metals are known to cause significant water pollution.

5. **Conclusion**:
- The salts of Mercury and Cadmium cause greater water pollution compared to the other pairs.

### Final Answer:
The salts of Mercury (Hg) and Cadmium (Cd) cause greater water pollution.

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