The de Broglie wavelength of an electron is given by the equation:
λ = h / mv
where λ is the wavelength, h is Planck's constant, m is the mass of the electron, and v is its velocity.
Substituting the given values, we get:
λ = h / mv
= (6.626 × 10^-34 J s) / (9.1 × 10^-31 kg)(7.0 × 10^6 m/s)
= 1.22 × 10^-10 m
Therefore, the wavelength of the electron is 1.22 × 10^-10 m.