How can you recognize EM radiation?

Answer 1

EM radiation can be detected by a variety of devices according to its frequency and its amplitude. For example, a radio receiver (Marconi effect) can be used to detect EM radiation in the radio range, your eyes or a photometer (photoelectric effect) for EM rads in the visible, IR and UV range, thermoluminescent detectors can be used for ionizing EMs, etc. One simple way to differentiate between EM radiation and particulate radiation is to place a plastic or thin metal shield between the detector and the source. Particulate radiation, such as alpha, beta, positron, typically will not penetrate plastic shielding, and your count rate or exposure levels will decrease. Whereas EMR is penetrable, and will traverse the plastic, needing something more substantial, such as lead, before showing signs of significant reduction in exposure.