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

Options

A. Less than `1`
B. greater than `1`
C. equal to `1`
D. depends on the mass of parent nucleus

Explanation

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

### Step-by-Step Solution:

1. **Understanding Fission**:
- In a fission reaction, a heavy nucleus (like Uranium-235) splits into two or more lighter nuclei (fission products), along with the release of energy and neutrons.

2. **Mass of Parent Nucleus**:
- The mass of the parent nucleus is the mass of the heavy nucleus before the fission occurs. For example, if we consider Uranium-235, its mass is approximately 235 atomic mass units (amu).

3. **Mass of Fission Products**:
- After fission, the heavy nucleus breaks into lighter nuclei (like Krypton and Barium) and some neutrons. The combined mass of these fission products is less than the mass of the parent nucleus.

4. **Mass-Energy Equivalence**:
- According to Einstein's mass-energy equivalence principle (E=mc²), the "missing" mass is converted into energy during the fission process. This energy is what powers nuclear reactors and atomic bombs.

5. **Calculating the Ratio**:
- The ratio of the mass of fission products to the mass of the parent nucleus can be expressed as:
\[ \text{Ratio} = \frac{\text{mass of fission products}}{\text{mass of parent nucleus}} \]
- Since the mass of the fission products is less than the mass of the parent nucleus, this ratio will always be less than 1.

6. **Conclusion**:
- Therefore, we conclude that in any fission process, the ratio of the mass of fission products to the mass of the parent nucleus is always less than 1.

### Final Answer:
\[ \text{Ratio} < 1 \]