Answer:
The de Broglie wavelength will remain the same because it does not depend on temperature.
Explanation:
de Broglie wavelength of a particle is independent of the temperature and hence the properties of emitted particle such as photoelectric effect, radioactive radiation etc. does not depend on the temperature.
Also, until unless the kinetic energy of a moving particle is not driven by the
thermal energy, the de Broglie wavelength is independent of the temperature