Which of the following statements about thermal radiation is always true?
A)A hot object emits photons with a higher average energy than a cool object.
B)A hot object emits more radio waves than a cool object.
C)A hot object emits more X- rays than a cool object.
D)A hot object emits photons with a longer wavelength than a cool object.

Question

Quizplus · Accepted Answer

Hot objects have a higher temperature, which means that the average kinetic energy of their atoms and molecules is higher. This translates to emitting photons with a higher average energy, or shorter wavelengths, according to the relationship between energy and wavelength given by the Planck's law of blackbody radiation. Option B does not hold true as radio waves have much longer wavelengths than the thermal radiation typically emitted by hot objects. Option C is also false, as X-rays require much higher energies than can be generated by thermal processes. Option D is incorrect as hotter objects emit photons with shorter wavelengths, not longer.

Which of the Following Statements About Thermal Radiation Is Always