C.As the two objects touch, thermal energy flows as heat from the warmer block to the colder block until particles in both blocks move at the same rate and reach the same temperature.
Explanation:
Heat is the transfer of thermal energy from an object at higher temperature to an object at colder temperature.
The temperature of an object is a measure of how fast the particles in the object move: the higher its temperature, the faster the particles move, the higher the average kinetic energy of the particles in the object. As a result, the particles of the object at higher temperature tend to transfer more energy (called thermal energy) to the particles of the object at colder temperature by colliding with them: this process continues until the particles of the colder object reach the same average kinetic energy as the particles of the warmer object, and this means that the two objects have reached the same temperature.
