Atomic Structure

Calculate the de Broglie wavelength of an electron in the first Bohr orbit of a hydrogen atom if the velocity of an electron in the first orbit is $2.2 \times 10^6 \text{ ms}^{-1}$. [mass of electron $= 9.1 \times 10^{-31}$ kg, plank's constant (h) $= 6.626 \times 10^{-34}$ J s]