Home › Forums › Hyperfine course › ERP › EPR on free atoms (2) › First task answer This topic has 0 replies, 1 voice, and was last updated 1 month ago by nvrafelg. Viewing 1 post (of 1 total) Author Posts April 26, 2025 at 3:29 pm #6594 nvrafelgParticipant The m_J value changes if the system absorbs a photon, but the total angular moment J stays the same. This means the orientation of J changes along the z-axis, but only in discrete increments Author Posts Viewing 1 post (of 1 total) You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In