Chem Lab

• Henri Becquerel - discovered uranium salts emits radiation which can cause fogging of photographic plates
• Radioactivity - spontaneous emission of radiation by an element
• Chemical Change

  • change in which atoms join together, split apart or rearrange
  • breaking of forming bonds between atoms
• Nuclear Change

  • change in which the nucleons change
  • turns one element into another element
  • change that occurs within the atom
• Nuclear Power - harnessing the energy stored in the powerful bonds between protons and neutrons to turn the lights on in our houses
• Nuclear Weapons - by harnessing the energy stored in the powerful bonds between protons and neutrons to destroy a city in less than a second
• Archaeology - determine the age of a fossil (carbon dating)
• Radiochemistry and nuclear medicine - make use of the fact that two different isotopes of the same element have the same identical properties even though they have different nuclear properties
• Cosmochemistry - change in the universe utilizes principles from nuclear chemisty
• Atom

  • proton
  • electron
  • neutron
• Atomic number - number of protons
• Identical Nuclides

  • atoms that have the same number of protons and neutrons
• Alpha Radiation - particles are emitted of helium nuclei which can be stopped by paper
• Beta Radiation - particles are emitted of high speed electrons by an unstable nucleus which can be stopped by aluminum
• Gamma Radiation - consists of high energy photons of very short wavelengths are emitted
• Positron Emission - a particle that has the same mass as electron but an opposite sign is emitted
• Electron Capture - electron is captured by the nucleus of an element from the electron cloud surrounding the nucleus
• X rays - radiation results from an energy released when electrons transfer from a higher to lower energy state
• Alpha Decay - emission of alpha particle, mass number decreases by 4, atomic number decreases by 2
• Beta Decay - emission of beta particles, no change in mass number but the atomic number increases by 1
• Neutron - proton ratio

  • more neutrons packed more neutrons needed to bind
• Radioactive Series - the radioactive elements can gain stability by single emission and successive emission creates a series
• Nuclear Transmutation - a neutron can change identity whenever it is struck by neutron or another nucleus
• Water Purification - process of removing undesirable chemicals
• Filtration is used to separate particles and fluid in a suspension
• Sedimentation - process using gravity to remove suspended solids from water
• Distillation - process of separating the components or substances from a liquid mixture by selective boiling and condensation