Articles > Oxidation definition – quiz Oxidation definition – quiz Quiz Choose the best answer. 1. Which of the following is an oxidation? Adding of an oxygen atom to a compound Removal of an electron from a compound A gain of electrons 2. A substance that undergoes reduction in redox reactions Oxidizing agent Reducing agent Redox agent 3. Electron acceptor Oxidizing agent Reducing agent Redox agent 4. Substance that undergoes oxidation in a redox reaction Oxidizing agent Reducing agent Redox agent 5. Electron donor Oxidizing agent Reducing agent Redox agent Send Your Results (Optional) Your Name To Email Time's up