In an electron microscope the electrons generate the

Question

image. For one of the scanning electron microscopes
in our Central Analytical Facility, the electrons are
accelerated to have a kinetic energy of 200,000 eV.
Electrons with this kinetic energy have a velocity of
2.67 x 10^8 m/s, almost 90% of the speed of light. What is the wavelength of the electrons traveling at this very high speed?

I know the right answer is 2.72 pm but I need help getting to that answer