nuclear chemistry aim nuke1 what is radioactivity?
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Nuclear Chemistry
Aim Nuke1What is radioactivity?
A Brief History of Nuclear Chem1895 - Wilhelm Roentgen – German
discovered “X-rays”, a powerful form of electromagnetic energy
1896 - Henri Becquerel - French
discovered radioactivity when he left uranium on top of photographic filmalso suffered radiation burns from a sample of radium in his pocket
A Brief History of Nuclear Chem
1898 - Henri and Marie Curie – French
using radiometry (the measure of electromagnetic energy strength and distribution)
separated uranium ore into different fractions
Discovered thorium, polonium (named for Poland, where Marie was originally from) and radium
A Brief History of Nuclear Chem
1899 - Ernst Rutherford - Englishshowed that radioactive decay can be described by a simple equation implying that a given radioactive substance has a characteristic "half-life"• the TIME taken for HALF THE AMOUNT of
radioactivity present in a source to decayHe also coined the terms alpha particle, beta particle, and gamma rays• he converted nitrogen into oxygen (first
example of artificial transmutation)Theorized there were particles called neutrons
A Brief History of Nuclear Chem
1932 James Chadwick Discovers Rutherford’s neutrons through experimentationHe shot alpha particles through a beryllium sheet, and through a layer of waxDetected protons at the end of the process
A Brief History of Nuclear Chem
1938 Otto Hahn, Lise Meitner, and Fritz Strassmann
became the first to split uranium atoms by bombarding them with neutronsMeasureable amounts of energy releasedCoined the name fission, after binary fission in biologySmall nuclear reaction!
A Brief History of Nuclear Chem
1939 Leo Szilard
Writes a letter with fellow scientists to President Franklin D. Roosevelt
• Warns of the potential of fission as a potentially devastating weapon
• Nazis in Germany were working already working on developing it
• Albert Einstein signs the letter to add his support
Result • Roosevelt authorizes a
small study into uranium. • US, UK, and Canada begin
work on the atomic bomb
A Brief History of Nuclear Chem
1942 Enrico Fermi successfully created the first man-made nuclear chain reaction Squash court under the stadium at the University of ChicagoAlso almost created the first nuclear meltdown On that same squash courtMeltdown • the nuclear material inside the reactor
overheats• Melts through building• Heads toward China• Also called the
“China Syndrome”
A Brief History of Nuclear Chem
1939-1945 The Manhattan Projecta research and development project that produced the first atomic bombs during
World War II. July 16th, 1945• Trinity Test at Los Alamos• First nuclear bomb test• Upon seeing the destructive power of the
atomic bomb, Robert Oppenheimer, project leader, quotes the Bhagavad Gita, a Hindu text, saying:
“Now I am become death, the destroyer of worlds”
A Brief History of Nuclear Chem
August 6th, 1945a uranium bomb, Little Boy, dropped on Hiroshima Japan
August 9th, 1945. a plutonium bomb, Fat Man, dropped on Nagasaki, Japan on
The cities are devastated, with up to 250,000 people dead. Japan surrenders unconditionally 6 days later, on August 15th, 1945.
Use of the atomic bombs ends World War II US does not have to invade Japan, saving millions of lives both Japanese and AlliedControversy still surrounds the decision to use the weapon even till today