given that the speed of light, denoted as c, is the maximum speed at which anything can travel, an electron cannot reach or exceed this speed. so you cannot determine the de brogile wavelength of an electron traveling at the speed of light. but you can calculate the de brogile wavelength of an electron with a non-relativistic speed
1 is the de brogile wavelength, h is planck's constant (approximately 6.626 × 10^-34 J•s)
m is the mass of the electron, and v is the velocity of the electron. to find the de brogile wavelength, u need the velocity of the electron. the question does not provide info about the velocity of the electron, only the speed of light
so you cannot calculate the de brogile wavelength based on the given info
