Quote: "In physics, electromagnetic radiation (EMR) consists of waves of the electromagnetic (EM) field, which propagate through space and carry momentum and electromagnetic radiant energy."
Transverse waves that are made up of oscillating electric and magnetic fields.
Quote: "Types of EMR include radio waves, microwaves, infrared, (visible) light, ultraviolet, X-rays, and gamma rays."
Quote: "In a vacuum, electromagnetic waves travel at the speed of light, commonly denoted c."
Quote: "In homogeneous, isotropic media, the oscillations of the two fields are perpendicular to each other and perpendicular to the direction of energy and wave propagation, forming a transverse wave."
Quote: "The position of an electromagnetic wave within the electromagnetic spectrum can be characterized by either its frequency of oscillation or its wavelength."
Quote: "In order of increasing frequency and decreasing wavelength these are: radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays."
Quote: "Electromagnetic waves are emitted by electrically charged particles undergoing acceleration."
Quote: "EM waves carry energy, momentum and angular momentum away from their source particle and can impart those quantities to matter with which they interact."
Quote: "EMR is sometimes referred to as the far field, as it is associated with those EM waves that are free to propagate themselves ('radiate') without the continuing influence of the moving charges that produced them."
Quote: "In this language, the near field refers to EM fields near the charges and current that directly produced them, specifically electromagnetic induction and electrostatic induction phenomena."
Quote: "In quantum mechanics, an alternate way of viewing EMR is that it consists of photons, uncharged elementary particles with zero rest mass which are the quanta of the electromagnetic field, responsible for all electromagnetic interactions."
Quote: "Quantum electrodynamics is the theory of how EMR interacts with matter on an atomic level."
Quote: "Quantum effects provide additional sources of EMR, such as the transition of electrons to lower energy levels in an atom and black-body radiation."
Quote: "The energy of an individual photon is quantized and is greater for photons of higher frequency. This relationship is given by Planck's equation E = hf."
Quote: "A single gamma ray photon, for example, might carry ~100,000 times the energy of a single photon of visible light."
Quote: "The effects of EMR upon chemical compounds and biological organisms depend both upon the radiation's power and its frequency."
Quote: "EMR of visible or lower frequencies (i.e., visible light, infrared, microwaves, and radio waves) is called non-ionizing radiation."
Quote: "The effects of these radiations on chemical systems and living tissue are caused primarily by heating effects from the combined energy transfer of many photons."
Quote: "High frequency ultraviolet, X-rays, and gamma rays are called ionizing radiation since individual photons of such high frequency have enough energy to ionize molecules or break chemical bonds."
Quote: "These radiations have the ability to cause chemical reactions and damage living cells beyond that resulting from simple heating, and can be a health hazard."