………………………………… element is concerned with photolysis of water.

Explanation

To solve the question regarding which element is concerned with the photolysis of water, follow these steps:

### Step-by-Step Solution:

1. **Understand Photolysis**: Photolysis refers to the process of splitting water molecules into hydrogen and oxygen in the presence of light. This process is crucial in photosynthesis.

2. **Identify the Element**: The question asks for an element involved in this process. In the context of photosynthesis, particularly in the light-dependent reactions, certain elements play a key role.

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