Why 2nd Electron Gain Enthalpy of oxygen is positive? Share with your friends Share 30 Shveta Dua answered this Kindly refer to the given link: https://www.meritnation.com/ask-answer/question/first-electron-affinity-for-oxygen-is-exothermic-but-seco/periodic-classification-of-elements/9807937 Regards 62 View Full Answer Nitin Gupta answered this Thanks with thumbs up 4