Compared to the mass of lightest nuclei, the mass of an electron is only (approximately)

Options

A. `1/80`
B. `1/800`
C. `1/1800`
D. `1/2800`

Answer

To solve the question of comparing the mass of an electron to the mass of the lightest nucleus (which is hydrogen), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Lightest Nucleus**:
- The lightest nucleus is that of hydrogen, which consists of a single proton.

2. **Understand the Mass of Hydrogen**:
- The mass of a hydrogen nucleus (proton) is approximately 1 atomic mass unit (amu), which is about 1.67 x 10^-27 kg.

3. **Know the Mass of an Electron**:
- The mass of an electron is approximately 9.11 x 10^-31 kg.

4. **Calculate the Ratio**:
- To compare the mass of an electron to that of hydrogen, we can set up the ratio:
\[ \text{Ratio} = \frac{\text{Mass of Electron}}{\text{Mass of Hydrogen Nucleus}} = \frac{9.11 \times 10^{-31} \text{ kg}}{1.67 \times 10^{-27} \text{ kg}} \]

5. **Perform the Calculation**:
- Performing the division gives:
\[ \text{Ratio} \approx \frac{9.11}{1670} \approx 0.000545 \]
- This can be approximated to:
\[ \text{Ratio} \approx \frac{1}{1800} \]

6. **Conclusion**:
- Therefore, the mass of an electron is approximately \( \frac{1}{1800} \) times the mass of the lightest nucleus (hydrogen).

### Final Answer:
The mass of an electron is approximately \( \frac{1}{1800} \) times the mass of the lightest nucleus.

---