What is electron affinity? Md. Saifur Rahman The energy emitted when we try to transform an element in its gaseous state into one mole negative ion by injecting one mole electron into its one mole atom is called the electron affinity.You may likeDo I need car insurance?What is car insurance?How could I get cheaper car insurance?What is auto insurance?Why Adulterant food is the barrier to sound health?What are the producers?What are food preservatives?What is food chain?What is tertiary consumer?