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Take out hwk & tables.

Take out hwk & tables. Compare answers to hwk sets. List 2 pieces of evidence that light is a wave. Diffraction Interference. List 1 piece of evidence that light is a stream of particles. Photoelectric effect. List 1 piece of evidence for the Bohr model of the atom.

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Take out hwk & tables.

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  1. Take out hwk & tables. Compare answers to hwk sets.

  2. List 2 pieces of evidence that light is a wave. • Diffraction • Interference. List 1 piece of evidence that light is a stream of particles. • Photoelectric effect List 1 piece of evidence for the Bohr model of the atom. • Emission or Absorption spectra

  3. Ref Table Page 3.

  4. Standard Model • Physicists have developed a theory called “The Standard Model” that explains what the world is and what holds it together.

  5. Standard Model • It was once thought that the fundamental particles were electrons, protons, neutrons. • Now more & smaller subatomic particles found – quarks & leptons that comprise matter. • Forces are carried by particles too!

  6. All matter classified Hadrons or LeptonsHadronsmade from quarks. p+ & no Quarks can’t exist alone.

  7. Protons, Neutrons: are baryons made of only up & down quarks. • Ex 1. How many up & down quarks in a p+? • Charge = +1 • Baryons have 3 quarks only. • 2 up & 1 down. • u + u + d • +2/3 +2/3 – 1/3 = +1

  8. Ex 2: How many up & down quarks in a no? • Charge = 0 • 1 up & 2 down. • u d d • +2/3 -1/3 -1/3 = 0

  9. The Atom

  10. Leptons • The most familiar member of this group is the electron e, but there are also heavier particles called the muon m and the tau t. • For each of those, there is a smaller “partner” called a neutrino n . • The leptons are all capable of independent existence.

  11. All particles have anti-particles same mass. • Antiparticles behave same as corresponding matter particles, except they have opposite charges. • A proton is electrically positive - an antiproton is negative. • Gravity affects matter and antimatter the same way. • If matter & corresponding antimatter meet, they annihilate into pure energy!

  12. Antimatter Notation add bar to antimatter: Mesons quark & antiquark.

  13. 3. A particle is composed of 2 charm, & 1 bottom quark. • What type of particle is it? • Write the symbols & charges for all the particles. • c c b • +2/3 +2/3 -1/3 What is its charge? • +1.

  14. 4. A particle is composed of 1 anti-strange, & 1 down quark. • Write the symbols & charges for all the particles. • What type of particle is it? • s d • +1/3 -1/3 What is it’s charge? • 0. • Meson.

  15. All independent particles must have whole number of elementary charge!

  16. Forces & Force Exchange Particles4 Fundamental Forces The universe exists because the fundamental particles interact. These interactions include 4 attractive & repulsive forces, decay, & annihilation. Force particles are gaugebosons. • Strong Nuclear (Nuclear) • Electromagnetic • Weak (Nuclear) • Gravity

  17. Strong Force • Short Range, Attractive only – holds nuclear particles together. • Particle = gluons.

  18. Electromagnetic Force • Long range. Attracts & repels charged particles (Coulomb’s Law). • Carrier particle = photon.

  19. Weak Force • In the nucleus. Involved with decay of particles. Short range. The carrier particles of the weak interactions are the W and Z bosons.

  20. Gravity • Long range weakest force. Attractive only. • The gravity force carrier particle has not been found. It, however, is predicted to exist and may someday be found: the graviton.

  21. Quarks & Leptons 5:40 min.http://www.youtube.com/watch?v=aTFCKbZw8QY Hwk: Read Text 25-4 pg 917-923 Do pg 923 #1,2 Pg 928 #30 – 37 Full sentences! 2. Bring back textbook!

  22. Summary: • EM energy can be thought of as tiny particles (photons) related to f. • E in EM radiation/photons E = hf. • Matter can be thought of as E stored in nucleus. • E in matter E = mc2. Joules. • 1 u = 931 MeV. 1 x 106eV = 1 MeV. • E measured in eV and J. • 1.6 x 10-19 J = 1 eV .

  23. The charge on the quark below would be: • +1 • -1 • +2/3 • -2/3

  24. This particle is a: • Lepton • Proton • Meson • neutron

  25. Cern Standard Modelhttp://www.youtube.com/watch?v=V0KjXsGRvoA&feature=related5 minutes

  26. Comprehensive Standard Model Summery(15 minutes)Cassiopeiahttp://www.youtube.com/watch?v=K6i-qE8AigE

  27. Quantum Song • http://www.youtube.com/watch?feature=player_detailpage&v=DZGINaRUEkU

  28. What is Higgs Boson 3:30 • http://www.youtube.com/watch?v=RIg1Vh7uPyw • What now for the Higgs 8:00 min w/ad. • http://www.youtube.com/watch?v=649iUqrOKuE

  29. Regents Problems Wksht.

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