The radioactive element used in heart pacemakers is
(1) Uranium
(2) Deuterium
(3) Plutonium
(4) Radium
Answer: (1) The actinides (or actinoids) are chemical elements with atomic numbers between 90 and 109 inclusively. They occur between Groups 3 and 4 in Period 7 of the periodic table. All elements in this family are radioactive. Five actinides, namely: thorium, protoactinium, uranium, neptunium, and plutonium, have been found in nature. Plutonium is used in the manufacture of nuclear weapons and as the power source in nuclear power plants. On a smaller scale, it is also used as a power source in smaller devices such as the heart pacemaker.
