Question

Calculate the kinetic energy of an alpha particle which has a wavelength of 12 pm.

Answer 1

by de Broglie's wavelength ,
lamda=h\mv
or
lamda = h\√2KEm
where lamda is wavelength
h is Planck's constant
m is mass of alpha particle (atomic mass of helium)
KE is kinetic energy.
now solve it by yourself for practice. Hope that this will help you.

Answer 2

in simple terms, alpha particle-He2+ ion, mass -4u,
now, kinetic energy=1/2mv^2
velocity of it can be found out by de Broglie relation- wavelength=h/mv,
& then, put the values in the ke formula to get the answer.