The kinetic energy of a moving electron is 180 eV, its linear momentum is about: (mass of 1 electron = $9 \times 10^{-31} kg$)

$6.6 \times 10^{-24} kg~ms^{-1}$

The correct answer is Option (3) → $6.6 \times 10^{-24} kg~ms^{-1}$

The kinetic energy is related to momentum (P) and mass (m) by -

$K.E.=\frac{P^2}{2m}$

$⇒P=\sqrt{2mK.E.}$

$=\sqrt{2×(9×10^{-31}kg)(2.88×10^{-17}J)}$

$≃6.6≃10^{-24}kg\,m/s$