What does the radiant energy of electromagnetic waves in the visible portion of the electromagnetic spectrum mean?

Answer 1

Radio waves(:

From Rafaelrz: Electromagnetic radiation is the propagation of vibrating electric and magnetic fields in the form of waves. Electromagnetic radiation has wave properties and has a whole series of frequencies. Visible light is only a small part of the whole spectrum ( The electromagnetic radiation spectrum ), from the wavelength of about 0.40 to 0.76 microns. Other radiations that conform this spectrum are; gamma radiation, x-rays, ultraviolet radiation, infrared radiation, microwaves, radio waves.

The term 'radiant energy' or 'radiant heat' is frequently used to refer to 'thermal

radiation', which is the range of the electromagnetic spectrum with wavelength

from about 0.1 to 100 microns. Notice that the spectrum of light lies in the spectrum of thermal radiation.

And so this radiation is responsible for heat transferbetween bodies at different temperatures separated by vacuum space (or transparent medium) . This is the radiation mechanism of heat transfer, being the other two important ones conduction and convection.