You have a box of filled with gas and by some process you double the number of atoms in the box, but now each one only has (on average) half as much energy as before the process started.

what has happened to the thermal energy and temperature of the gas, respectively?

-thermal energy increased, temperature decreased.

-thermal energy decreased, temperature unchanged.

-thermal energy unchanged, temperature unchanged.

-thermal energy unchanged, temperature decreased.

Option-(D):Thermal energy unchanged, temperature decreased.

Explanation:

Thermal energy and Temperature,T:

Thermal energy of the system is remained unchanged while the temperature,T of the objects present inside the system is more associated with the objects fundamental properties which each matter shows or exhibits in nature.

While the thermal energy is the flow or exchange of thermal or heat energy between the different objects in interaction to each other.

answer; how far out of place which the object finished relative to the starting location;