In the particlesof the medium move …

Heat is transmissible. It flows from body to body. Transfer of heat takes place in all solids, liquids and gases. Heat transfer may take place in three ways- i. When the particles are not moving at all. ii. When the particles move about. iii. When heat transfers from one body to another body that are placed at a distance without heating any medium between the two bodies. a. Conduction- The process of transmission of heat energy in solids without the actual movement of particles from their positions is called conduction. This usually happens when a body is in direct contact with the hot body. b. Convection- Convection takes place in liquids and gases only as the particles are free to move. The phenomenon due to which particles of a medium actually move to the source of heat energy and on absorbing heat energy, move away from it thereby making space for other particles to move to the source of heat energy is called convection. One natural application of convection is the occurrence of land breeze and sea breeze. c. Radiation: The transference of heat energy from a hot body to a cold body directly, without heating the space in between the two bodies, is called radiation. As a matter of fact, radiation requires no medium. For e.g. the vast space between the earth and the sun is a vacuum; yet the heat of the sun reaches earth.