radiating abilities and absorb energy??

Question

what statement can you make about the radiating ability of a substance if you know its ability to absorb energy.

Answer 1

An object that absorbs all the radiation that it receives is known as a black body. This is because no energy is re-emitted. An object that reflects all the radiation it receives is known as a white body. Most objects will absorb some energy (inferred short wave) and re-emit inferred long wave at a steady rate. The re-emittance is felt as heat. Most objects are then classed a grey bodies, both absorbing and re-emitting some energy. Think of concrete and how it stays warm even after the sun has gone down and is no longer receiving energy from the sun.