3. as an object’s temperature increases, the at which it radiates energy increases.

An increase in temperature of the object’s, increases the RATE that radiates energy.

Explanation:

The difference in the temperature of the object is the main reason for transfer of heat energy from one to the other. The overall average of kinetic energy produced by the particles that exits in a substance is known to be temperature.  

The temperature may be either cold or hot. When there is a rise or increase in an object's temperature, there will be an increase in rate at which it radiates or emits energy.  The molecule in the object moves when it gets heated.

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.