A: Mass of 1 gram molecule of `H_(2)SO_(4)` is 98 gram.
R: One gram atom contains `N_(A)` atoms.

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 (A) and the reason (R) given in the statement.

### Step-by-Step Solution:

1. **Understanding the Assertion (A)**:
- The assertion states that the mass of 1 gram molecule of \( H_2SO_4 \) is 98 grams.
- A "gram molecule" refers to one mole of a substance. Therefore, 1 gram molecule of \( H_2SO_4 \) is equivalent to 1 mole of \( H_2SO_4 \).

2. **Calculating the Molecular Weight**:
- The molecular weight of \( H_2SO_4 \) (sulfuric acid) can be calculated as follows:
- Hydrogen (H): 2 atoms × 1 g/mol = 2 g/mol
- Sulfur (S): 1 atom × 32 g/mol = 32 g/mol
- Oxygen (O): 4 atoms × 16 g/mol = 64 g/mol
- Total molecular weight = 2 + 32 + 64 = 98 g/mol.

3. **Verification of the Assertion**:
- Since the molecular weight of \( H_2SO_4 \) is 98 g/mol, it confirms that the mass of 1 gram molecule (or 1 mole) of \( H_2SO_4 \) is indeed 98 grams. Thus, the assertion is **true**.

4. **Understanding the Reason (R)**:
- The reason states that one gram atom contains \( N_A \) atoms, where \( N_A \) is Avogadro's number (approximately \( 6.022 \times 10^{23} \)).
- A "gram atom" also refers to one mole of an element. Therefore, one gram atom of any element contains \( N_A \) atoms.

5. **Verification of the Reason**:
- Since one mole of any substance contains \( N_A \) entities (atoms, molecules, etc.), the reason is also **true**.

6. **Conclusion**:
- Both the assertion and reason are true. However, the reason does not provide a correct explanation for the assertion since the assertion is specifically about the mass of a molecule, while the reason discusses the number of atoms in a mole.

### Final Answer:
- The correct option is that both A and R are true, but R is not a correct explanation of A.