An electron has a mass of $9.1 \times 10^{-31}$ kg. It revolves round the nucleus in a circular orbit of radius $0.529 \times 10^{-10}$ metre at a speed of $2.2 \times 10^6$ m/s. The magnitude of its linear momentum in this motion is

$2.0 \times 10^{-24}~kg-m/s$

Linear

$=m v =9.1 \times 10^{-31} \times 2.2 \times 10^6$

$=2.0 \times 10^{-24} ~kg-m/s$