About radiation

Radiation as used in physics, is energy in the form of waves or moving subatomic particles. (Quantum mechanics predicts that waves can exhibit particle behavior (photons for example) and particles can exhibit wave behavior (De Broglie Wave for example), this is commonly called Wave-particle duality). Radiation can be ionizing or non-ionizing radiation, depending on its effect on atomic matter. The most common use of the word "radiation" refers to ionizing radiation. Ionizing radiation has enough energy to ionize atoms or molecules while non-ionizing radiation does not. Radioactive material is a physical material that emits ionizing radiation.
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Yes. Each object emits as much energy as it absorbs.