Radiation refers to the phenomenon that part of electromagnetic energy (electromagnetic wave, etc.) is emitted by the emission source. ) does not return to the field source after being far away from the field source, and the energy propagates outward in the form of electromagnetic waves or particles (such as α particles and β particles).
All objects in nature, as long as the temperature is above absolute zero (about -273. 15 degrees Celsius), are constantly transferring heat in the form of electromagnetic waves and particles. This way of transferring energy is called thermal radiation.
Ionizing radiation
Radiation with high enough energy can ionize atoms. Generally speaking, ionization means that electrons are knocked out of the electron layer by ionizing radiation, making atoms positively charged. Because cells are made of atoms, ionization can cause cancer. A cell consists of trillions of atoms. The probability that ionizing radiation causes cancer depends on the radiation dose rate and the sensitivity of the organism receiving radiation. Alpha, beta, gamma radiation and neutron radiation can all be accelerated to high enough energy to ionize atoms.
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