In any fission the ratio
`("mass of fission produts")/("mass of parent nucleus")` is

Options

A. Greater than 1
B. Depends on the mass of the parent nucleus
C. Equal to 1
D. Less than 1

Answer

To solve the problem regarding the ratio of the mass of fission products to the mass of the parent nucleus in a fission reaction, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Fission**: In a fission reaction, a heavy nucleus (the parent nucleus) splits into two or more smaller nuclei (the fission products). This process also releases a significant amount of energy.

2. **Mass of Parent Nucleus**: Let’s denote the mass of the parent nucleus as \( M_p \).

3. **Mass of Fission Products**: After the fission process, the resulting smaller nuclei (fission products) will have a combined mass denoted as \( M_f \).

4. **Mass-Energy Equivalence**: According to Einstein’s mass-energy equivalence principle (\( E = mc^2 \)), some mass is converted into energy during the fission process. This means that the total mass of the fission products is less than the mass of the original parent nucleus.

5. **Inequality of Masses**: Therefore, we can express this relationship mathematically:
\[ M_f < M_p \]
This indicates that the mass of the fission products is always less than the mass of the parent nucleus.

6. **Calculating the Ratio**: The ratio of the mass of fission products to the mass of the parent nucleus can be expressed as:
\[ \text{Ratio} = \frac{M_f}{M_p} \]

7. **Conclusion**: Since \( M_f < M_p \), it follows that:
\[ \text{Ratio} < 1 \]
This means that the ratio of the mass of fission products to the mass of the parent nucleus is always less than one.

### Final Answer:
The ratio \( \frac{\text{mass of fission products}}{\text{mass of parent nucleus}} \) is less than one.