What is the (i) speed (ii) Momentum (iii) de- Broglie wavelength of an electron having kinetic energy of 120 eV ?

Explanation

To solve the problem of finding the speed, momentum, and de Broglie wavelength of an electron with a kinetic energy of 120 eV, we will follow these steps:

### Step 1: Convert Kinetic Energy from eV to Joules
The kinetic energy (KE) in electronvolts (eV) needs to be converted to joules. The conversion factor is:
\[ 1 \text{ eV} = 1.6 \times 10^{-19} \text{ J} \]

Thus, for 120 eV:
\[
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