An electron, an `alpha`-particle and a proton have the same kinetic energy. Which of these particles has the largest de-Broglie wavelength?

Explanation

To determine which particle among an electron, an alpha particle, and a proton has the largest de-Broglie wavelength when they all have the same kinetic energy, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the de-Broglie Wavelength Formula**:
The de-Broglie wavelength (λ) is given by the formula:
\[
\lambda = \frac{h}{p}
...