Assertion: The splitting of water is associated with PS II.
Reason: Water is split into `H^(+),O_(2)` and electrons.

Answer

### Step-by-Step Solution:

1. **Understanding the Assertion**: The assertion states that the splitting of water is associated with Photosystem II (PS II). This means that PS II plays a crucial role in the process of photolysis of water during photosynthesis.

2. **Understanding the Reason**: The reason given is that water is split into hydrogen ions (H⁺), oxygen (O₂), and electrons. This describes the chemical process that occurs during the photolysis of water.

3. **Mechanism of Water Splitting**: When chlorophyll in PS II absorbs light energy (photons), it becomes excited. This energy is used to split water molecules (H₂O) into their components: hydrogen ions (H⁺), oxygen (O₂), and electrons (e⁻).

4. **Chemical Equation**: The overall reaction for the splitting of water can be represented as:
\[ 2H_2O \rightarrow 4H^+ + 4e^- + O_2 \]
This reaction indicates that two molecules of water yield four hydrogen ions, four electrons, and one molecule of oxygen.

5. **Role of Electrons**: The electrons produced from the splitting of water replace the electrons lost by chlorophyll in PS II during the light reactions of photosynthesis. This is essential for the continuation of the photosynthetic process.

6. **Conclusion**: Both the assertion and the reason are correct. The splitting of water is indeed associated with PS II, and it results in the production of hydrogen ions, oxygen, and electrons.

### Final Statement:
- **Assertion**: True
- **Reason**: True
- **Explanation**: The reason accurately explains the assertion.