Atomic emission is the process of releasing energy in the form of electromagnetic radiation or particles from atoms. The two crossword solutions for this term are ION (3 letters) and GAMMARAY (8 letters). An ION is an atom or molecule that has gained or lost one or more electrons, giving it a net positive or negative electrical charge. Gamma rays are a form of electromagnetic radiation with a very short wavelength and high frequency, which is emitted from the nucleus of an atom during radioactive decay.