A: 1 gram of salt in `1 m^(3)` of solution has concentration of 1 ppm.
R: ppm is defined as number of parts by mass of solute per million parts of solution.

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion
B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion
C. If Assertion is true statement but Reason is false
D. If both Assertion and Reason are false statements

Answer

To solve the question, we need to analyze both the assertion and the reason provided.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "1 gram of salt in 1 m³ of solution has a concentration of 1 ppm."
- To understand this, we need to recall the definition of ppm (parts per million).

2. **Definition of ppm**:
- Ppm is defined as the number of parts by mass of solute per million parts of solution.
- Mathematically, it can be expressed as:
\[ \text{ppm} = \left( \frac{\text{mass of solute (g)}}{\text{mass of solution (g)}} \right) \times 10^6 \]

3. **Calculating the concentration**:
- In this case, we have 1 gram of salt (solute) in 1 m³ of solution.
- Since 1 m³ of water is approximately equal to 1,000,000 grams (1 m³ of water has a mass of about 1,000 kg or 1,000,000 g), we can substitute this into the ppm formula:
\[ \text{ppm} = \left( \frac{1 \text{ g}}{1,000,000 \text{ g}} \right) \times 10^6 = 1 \text{ ppm} \]
- Therefore, the assertion is correct.

4. **Understanding the Reason**:
- The reason states that "ppm is defined as the number of parts by mass of solute per million parts of solution."
- This is indeed the correct definition of ppm, confirming that the reason is also correct.

5. **Conclusion**:
- Since both the assertion and the reason are true, and the reason correctly explains the assertion, we conclude that the first option is correct.

### Final Answer:
Both the assertion and the reason are true, and the reason is the correct explanation of the assertion.