Final answer:
Heat is transferred from hot metal to water in a calorimeter through thermal conduction from the particles of higher kinetic energy in the metal to those with lower kinetic energy in the water, until thermal equilibrium is achieved.
Step-by-step explanation:
At the particle level, when a hot metal is placed into the water of a calorimeter, heat transfer occurs through the process of thermal conduction. Heat, also known as thermal energy, is transferred from the higher temperature of the metal to the lower temperature of the water due to the temperature difference between them. The metal's kinetic energy is higher because its particles are moving more vigorously. As the metal particles come into contact with the water particles, energy is transferred, causing the water particles to move faster, which results in an increase in the water's temperature. At the same time, the metal cools down as it loses energy to the water. This exchange continues until thermal equilibrium is reached, meaning both the metal and the water have the same temperature and there is no net heat flow between them.