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NUCLEAR AGE TIMELINE 2 Meaning Phrases (source U.S. Department of Energy) 1946 Winston Churchill proclaims an "iron curtain" across Europe. Atomic Energy Act (AEA) is passed. The Atomic Energy Commission (AEC) replaces the Manhattan Project. Further development of nuclear technology placed under civilian control. United States tests a nuclear bomb on Bikini Atoll. Oak Ridge produces radioactive compounds for medical diagnosis and treatment, research and industrial applications. 1948 Nuclear tests in the South Pacific. United States produces 50 nuclear bombs Berlin airlift 1949 National Chinese forces led by Chiang Kai-shek retreat to Formosa. Soviet Union detonates its first atomic device. 1950 Atomic Energy Commission develops the hydrogen bomb. Senator Joseph McCarthy attacks communism in America.

"McCarthyism" is born. The Korean War begins. 1951 Electricity is produced at the National Reactor Station from nuclear fission. 1952 Operations begin at the Savannah River Plant in Aiken, South Carolina. 1953 President Eisenhower proposes joint international cooperation to develop peaceful applications of nuclear energy. 1954 U.S. Secretary of State John Foster Dulles announces U.S. policy to Communist aggression will be massive retaliation. A nuclear submarine the U.S.S. Nautilus launches. Senator McCarthy is publicly disgraced in TV hearings. Atomic Energy Act promotes the peaceful use of nuclear energy through private enterprise Arco, Idaho becomes the first U.S. town to be powered by nuclear energy. 1956 Hungarian revolution crushed by Soviet tanks. Soviet Premier Nikita Khrushchev tells the West, "History is on our side. We will bury you."

THE STRONG NUCLEAR FORCE 1 Meaning Clusters Nucleons are very close together. Gravitational attraction is too small to account for stability. Scientists believe “the strong nuclear force” holds the nucleus together. This attractive force acts between protons and neutrons. For atoms with low atomic numbers, the ratio of neutrons to protons is close to one. For the larger atoms the number of protons increases so the number of neutrons increases at a greater rate. The ratio becomes much greater than one. Electrical repulsion in elements with more than 82 protons is too great for the strong nuclear force to hold the nucleus together. There are no completely stable isotopes after lead.

MEMORY TRIGGERS TESTS Nucleons___________________________ ___________________________________ Gravitational________________________ ___________________________________ attractive___________________________ ___________________________________ atoms______________________________ ___________________________________ ________________neutrons____________ ___________________________________ ______________protons_______________ ___________________________________ ratio_______________________________ ___________________________________ ______________repulsion_____________ ___________________________________ Source NASA Speed Learning format by Carl Peterson ©2005

NUCLEAR FUSION 1 Meaning Clusters The elements in the universe were created by nucleosynthesis. In stars nuclear fusion combines lighter elements to make heavier elements. Our sun fuses hydrogen to create helium. Leftover matter converts to energy such as visible light. Albert Einstein’s equation E = mc^2can calculate the amount of energy released. To find the value “m” subtract the mass of the newly formed nucleus from the sum of the masses of it’s parent particles. The formation of lighter elements between helium and iron on the periodic table is exothermic. Exothermic reactions release energy. Energy from the Sun powers almost every physical and biological cycle on Earth.

MEMORY TRIGGERS TESTS elements____________________________ ___________________________________ nuclear_____________________________ ___________________________________ hydrogen___________________________ ___________________________________ matter_____________________________ ___________________________________ Einstein’s__________________________ ___________________________________ calculate____________________________ ___________________________________ mass_______________________________ ___________________________________ formation___________________________ ___________________________________ Exothermic_________________________ ___________________________________ Source NASA Speed Learning format by Carl Peterson ©2005

HALF-LIFE 1 Meaning Clusters Statistics predict the decay of a large amount of radioactive nuclei. Half of the nuclei will decay in a specific period of time. This period is the half-life. Isotopes are halved over and over until practically all of the radioactive atoms decay. Half-life approximates the age of once-living matter. Cosmic ray protons strike the nucleus of an atom and generate a free neutron. Free neutrons strike a nitrogen-14 nuclei which emits a proton and changes into radioactive carbon-14. Carbon-14 atoms become part of the food cycle when they combine with oxygen to form carbon dioxide. The amount of carbon-14 stays the same because organisms replenish decayed carbon-14 during respiration or photosynthesis.

MEMORY TRIGGERS TESTS Statistics___________________________ ___________________________________ Half_______________________________ ___________________________________ Isotopes____________________________ ___________________________________ __________________radioactive________ ___________________________________ ___________approximates_____________ ___________________________________ Cosmic ray_________________________ ___________________________________ _________neutrons___________________ ___________________________________ Carbon-14__________________________ ___________________________________ combine____________________________ ___________________________________ organisms__________________________ ___________________________________ Source NASA Speed Learning format by Carl Peterson ©2005

Archimedes 287—212 B.C. Syracuse, Sicily Greek mathematician, astronomer, philosopher, physicist and engineer Designed war engines to defend Syracuse against Roman siege in Punic Wars Could move fully loaded ship by pulling one rope Discovered principles of density and buoyancy while taking a bath Invented irrigation device called Archimedes’ screw Invented numeral system write numbers up to 10^64 His calculations precursors to integral calculus Calculated what would be known as pi First known calculation of a geometric series First mathematical physicist Principles of buoyancy, lever, equilibrium, center of gravity Constructed sky maps and planetariums

MEMORY TRIGGERS Greek__________________________________ _______________________________________ Syracuse________________________________ _______________________________________ Mathematician___________________________ _______________________________________ War engines_____________________________ _______________________________________ Punic Wars______________________________ _______________________________________ Density and buoyancy_____________________ _______________________________________ Screw__________________________________ _______________________________________ Numeral system__________________________ _______________________________________ Pi_____________________________________ _______________________________________ Equilibrium_____________________________ _______________________________________ Center of gravity_________________________ _______________________________________ Planetarium_____________________________ _______________________________________