Introduction to Physical Science Monday, Wednesday, Thursday Tom Burbine [e-mail]

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Introduction to Physical ScienceMonday,
Wednesday, ThursdayTom Burbinetomburbine_at_astr
o.umass.edu
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• Fission Splitting of the nucleus of a heavy
  atom with the release of energy
• Fusion Combination of the nuclei of light atoms
  to form heavier nuclei with the release of energy

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Energy Source for Sun

• Fusing hydrogen into helium
• Hydrogen nucleus 1 proton
• Helium nucleus 2 protons, 2 neutrons
• Need high temperatures for this to occur
• 10 to 14 million degrees Kelvin

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http//www.astronomynotes.com/starsun/s3.htm
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http//www.astronomynotes.com/starsun/s3.htm
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How does Fusion Convert Mass to Energy

• What is the most famous formula in the world?

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E mc2

• m is mass in kilograms
• c is speed of light in meters/s
• E (energy) is in joules
• very small amounts of mass may be converted into
  a very large amount of energy

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Who came up with it?
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http//msnbcmedia3.msn.com/j/msnbc/Components/Phot
os/z_Projects_in_progress/050418_Einstein/050405_e
instein_tongue.widec.jpg
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Law

• Law of Conservation of mass and energy
• Sum of all mass and energy (converted into the
  same units) must always remain constant during
  any physical process

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Reaction

• 4 protons ? helium-4 2 neutrinos energy

Neutrino-virtually massless, chargeless particles
Positron-positively charged electron
annihilated immediately by

colliding with an electron
to
produce energy
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Antiparticles

• Antiparticle particle with the same mass and
  opposite electric charge
• Antiparticles make up antimatter
• Annihilation when a particle and an
  antiparticle collide
• Antimatter is said to be the most costly
  substance in existence, with an estimated cost of
  62.5 trillion per milligram.

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Fusion reaction

• Much more complicated than
• 4 protons ? helium-4 2 neutrinos energy

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Deuteron Deuterium (hydrogen with a
neutron) nucelus
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Proton-Proton Chain Reaction

• This reaction occurs 1038 times each second
• It if occurred faster, Sun would run out of fuel

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Neutrinos

• Neutrinos almost massless particles
• No charge
• It takes a neutrino about 2 seconds to exit the
  Sun

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Fusion

• The rate of nuclear fusion is a function of
  temperature
• Hotter temperature higher fusion rate
• Lower temperature lower fusion rate
• If the Sun gets hotter or colder, it may not be
  good for life on Earth

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What is happening to the amount of Helium in the
Sun?

• A) Its increasing
• B) its decreasing
• C) Its staying the same

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What is happening to the amount of Helium in the
Sun?

• A) Its increasing
• B) its decreasing
• C) Its staying the same

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Valence Electrons

• Electrons in the outermost occupied shell of an
  atom
• Forms chemical bonds

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Ion

• Ion an electrically charged particle created
  when an atom either loses or gains one or more
  electrons

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Ionic Bond

• Ionic bond chemical bond in which an attractive
  electric force holds an opposite charge together

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Covalent Bond

• Covalent bond a chemical bond in which atoms
  are held by their mutual attraction for two or
  more electrons share
• Covalent bonds form molecules

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Metallic Bonds

• A chemical bond in which positively charged metal
  ions are held together within a fluid
• Electromagnetic interaction between conduction
  electrons and gathered in an "electron sea
• Atoms "share" electrons that float about in a
  general electron cloud

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Charges need to balance

• Na ions carry a 1 charge
• Cl ions carry a -1 charge
• Na Cl- ? NaCl (Sodium chloride)

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• HCl Hydrogen Chloride
• Li2O Lithium Oxide
• CO Carbon Monoxide
• CO2 Carbon Dioxide

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Any Questions?