The mass of an electron is _______ times that of mass of a proton.

Explanation

To find out how many times the mass of an electron is compared to the mass of a proton, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Mass of an Electron and Proton**:
- The mass of an electron is \( 9.61 \times 10^{-31} \) kg.
- The mass of a proton is \( 1.67 \times 10^{-27} \) kg.

2. **Set Up the Ratio**:
- We need to find how many times the mass of an electron is compared to the mass of a proton. This can be expressed as:
\[ \text{Ratio} = \frac{\text{Mass of Electron}}{\text{Mass of Proton}} \]

3. **Substitute the Values**:
- Substitute the known values into the ratio:
\[ \text{Ratio} = \frac{9.61 \times 10^{-31} \text{ kg}}{1.67 \times 10^{-27} \text{ kg}} \]

4. **Calculate the Ratio**:
- Perform the division:
\[ \text{Ratio} \approx 0.0000575 \]

5. **Express the Result**:
- To express how many times the mass of an electron is compared to the mass of a proton, we can take the reciprocal of the ratio:
\[ \text{Mass of Electron} = \frac{1}{1838} \text{ times the mass of Proton} \]

### Final Answer:
The mass of an electron is approximately \( \frac{1}{1838} \) times that of the mass of a proton.