Nuclear Energy Nuclear Structure and Radioactivity

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

Il. Review - Atomic Structure Recognize Me? Atomic Structure: Atoms contain protons, neutrons and electrons 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.

III. Radioactivity Definition: The emission of radiation due to the breakdown of atomic nuclei 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

IV. Radiation Definition: Energy that is radiated or transmitted in the form of rays, waves or particles Types of Radiation Alpha () Particle : Nucleus of a helium atom; Charge of +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 

IV. Radiation    B. Types of Radiation 2. Beta ( Particle : High speed electron Charge of -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 

IV. Radiation    B. Types of Radiation 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  

Radiation Summary Slide

V. Energy Generated From Nuclear Fission Definition: The splitting of large atomic nuclei into smaller fragments 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

VI. Energy Generated From Nuclear Fusion Definition: The combining of small atomic nuclei to form larger ones 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?