Question

what is conduction convection and radiation?

Answer 1

Conduction: It is the flow of heat or transfer of heat energy through contact of a source of heat and a surface. it can be seen when a metal is heated while kept in flames.

Convection: It is flow of heat or transfer of heat without any actual contact between the source and the surface of other object. it can be seen when objects get heated while being away from the source. it happens because particles of air carry heat energy.
Radiation: it is the flow of heat or transfer of heat without help of any particles or any surface coming in contact with energy source. Radiation is the only one of the three that can travel in vacuum. It is the method through which heat is transferred from sun to our Earth or any other planet.

Answer 2

Answer:

the process by which heat or electricity is directly transmitted through the material of a substance when there is a difference of temperature or of electrical potential between adjoining regions, without movement of the materials conduction.

the movement caused within a fluid by the tendency of hotter and therefore less dense material to rise, and colder, denser material to sink under the influence of gravity, which consequently results in transfer of heat. convection.

Radiation is energy that comes from a source and travels through space and may be able to penetrate various materials. ... The kind of radiation discussed in this document is called ionizing radiation because it can produce charged particles (ions) in matter. Ionizing radiation is produced by unstable atoms.