Name the compound that contain Mg and helps green plants during photosynthesis.

Explanation

**Step-by-Step Solution:**

1. **Identify the Elements Involved**: The question asks for a compound that contains magnesium (Mg) and is involved in photosynthesis.

2. **Understand the Role of Magnesium in Plants**: Magnesium is an essential nutrient for plants, primarily because it is a central component of chlorophyll, the pigment responsible for photosynthesis.

3. **Define Photosynthesis**: Photosynthesis is the process by which green plants convert light energy into chemical energy, using carbon dioxide and water, and producing glucose and oxygen.

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