One of the following is a non essential element which counteract the toxicity of copper and stimulate plant growth

Options

A. Silica
B. Aluminium
C. Sodium
D. Nickel

Answer

To solve the question regarding which non-essential element counteracts the toxicity of copper and stimulates plant growth, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks for a non-essential element that can counteract copper toxicity and promote plant growth.

2. **Identify the Options**: The options provided are silica, aluminium, sodium, and nickel. We need to evaluate each of these elements to determine which one fits the criteria.

3. **Define Non-Essential Elements**: Non-essential elements are those that are not required for the normal growth and development of plants but can still have beneficial effects.

4. **Analyze Copper Toxicity**: Copper toxicity can lead to several negative effects on plants, including stunted growth, bluish coloration, yellowing or browning of leaves, reduced seed germination, and decreased iron intake.

5. **Evaluate Each Element**:
- **Silica**: While it can have some beneficial effects, it is not known specifically for counteracting copper toxicity.
- **Aluminium**: Generally considered harmful to plants and does not counteract copper toxicity.
- **Sodium**: Recognized as a non-essential element that can help mitigate the effects of copper toxicity and stimulate plant growth.
- **Nickel**: Also a non-essential element, but it does not specifically counteract copper toxicity.

6. **Conclusion**: Based on the analysis, sodium is the non-essential element that counteracts the toxicity of copper and stimulates plant growth.

### Final Answer:
**Sodium**