Description : Which of the following is a radioactive element? (1) Cobalt (2) Uranium (3) Argon (4) Chromium
Last Answer : (2) Uranium Explanation: Uranium (U) is a naturally occurring radioactive element. Its nucleus is unstable, so the element is in a constant state of decay, seeking a more stable arrangement ... fission reaction. In fact, uranium was the element that made the discovery of radioactivity possible.