Which of the following is not a key characteristics of thermal equilibrium? two objects must be in contact with each other
they must be at the same temperature
There must be no net thermal energy transfer
They must have different temperature

Why do scientists believe that light is made of streams of particles? scientists believe that light is made of streams of particles because only the presence of photons can explain phenomena observed during experiments on the photoelectric effect. these observations include only some frequencies of light causing the ejection of electrons, no time gap existing between light striking a metal and electrons being ejected, and intensity having no effect on the kinetic energy of the ejected electrons.

Need in all of themmm only answer if you know plsssss

Explain earth's motion, using the terms "precession" and "rotation" in your answer.