2. Nuclear Energy Nuclear Structure and Radioactivity

3. A.Atomic Number: The number of protons in the nucleus of an atom B.Atomic Mass: The sum of the mass of protons, neutrons and electrons in the atom # of neutrons = atomic mass - atomic number I. Review - Periodic Table

4. Il. Review - Atomic Structure RecognizeMe? A.Atomic Structure: Atoms contain protons, neutrons and electrons B.Isotopes: The number of neutrons in an atom is not always the same! Atoms of the same elements that have an abnormal number of neutrons are called Isotopes.

5. III. Radioactivity A.Definition: The emission of radiation due to the breakdown of atomic nuclei B.Description of Process: Isotopes and large atoms are unstable and will break apart New, lighter atoms are formed, releasing radiation in the process Unstable atoms will continue to break down until they become stable

6. IV. Radiation A.Definition: Energy that is radiated or transmitted in the form of rays, waves or particles B.Types of Radiation (  ) 1.Alpha (  ) Particle : Nucleus of a helium atom; Charge (+2); Mass of 4 Alpha decay occurs because the nucleus has too many protons which causes excessive repulsion. An alpha particle is emitted to reduce this. The atomic # of the decaying atom decreases by 2 and the mass decreases by 4 Symbol   

7. IV. Radiation B.Types of Radiation  2.Beta (  Particle : High speed electron Charge (-1); No measurable mass Beta decay occurs when the neutron to proton ratio is too great and causes instability. A beta particle is emitted, converting a neutron into a proton. The atomic # of the decaying atom increases by 1and the mass does not change Symbol   

8. IV. Radiation B.Types of Radiation (  ) 3.Gamma (  ) Ray : High energy photon (wave) No charge; No measurable mass Gamma decay occurs because the nucleus is at too high an energy. A gamma ray is emitted as the nucleus falls to a lower energy state. The atomic number and mass of the decaying atom do not change Symbol   

9. Radiation Summary Slide

10. V. Energy Generated From Nuclear Fission A.Definition: The splitting of large atomic nuclei into smaller fragments B.Description of Process: A large atom is struck by a single neutron Fission products include smaller atoms, neutrons and heat energy Uranium-235 is the most common isotope used to generate useable nuclear energy in power plants

11. VI. Energy Generated From Nuclear Fusion A.Definition: The combining of small atomic nuclei to form larger ones B.Description of Process: The mass of the combination is less than the sum of the masses of the individual nuclei. Mass is converted into energy! Takes place continuously in the sun and stars (H is converted into He) For energy production on earth, the nuclei of two isotopes of hydrogen are used: Deuterium and Tritium C.Energy Released from Nuclear Fusion: 10 grams of Deuterium which can be extracted from 500 liters of water could produce enough fuel for the lifetime electricity needs of an average person in an industrialized country. Do we use fusion to generate electricity?