Discovery of the particle Zoo and the Standard model of the Atom 202i] Name: \"expand taxthoxes before printing iyou ore handing in hand written work\" Key resources {see DEL content for links): Perimeter Institute "Beyond the Atom" Pearson chapter 1? Cassiopeia Project "Standard model" The particle adventure website I- I I O This assignment has 4 parts that will be completed over multiple classes: Video summary how our models need to change over time Discovery and detection of the vast array of particles The standard model provides an explanation and structure to the observation witnessed The development of models of the structure of matter is ongoing. '0'. Part 1: Making discoveries result in remodeling Learning outcome: D4-lsts: explain that concepts. models and theories are often used in interpreting and explaining observations and in predicting future observations D4-25ts: explain that scientific knowledge is subject to change as new evidence becomes apparent and as laws and theories are tested and subsequently revised, reinforced or rejected Watch Pen'meter Institute oi Theoretical Physics' W and Complete the Perimeter Institute illiclivitgtr l worksheet: Wm Beyond the atom: remodeling particle physics (Perimeter lnstirute of Theoretical Physics] pit-El. Reprodured with permission. 01. The model of the atom has changed over the past 150 years as new evidence has been found. Drainr labelled diagrams for a helium atom using each ol these models. Dalton's model of indivi-sihle Thomson's model using Rudierford's model using halls of matter electrons in a positive mass electrons and nuclei U2. Rutherford red alpha panicles at gold foil and was surprised by the results. He developed the nuclear model of the atom because (a) most of the alpha particles went through. (b) most of the alpha particles bounced back. to) a few of the alpha panicles went through. (d) a few of the alpha particles bounced back. 03. The Large Hadron lCollider (LHC) accelerates particles to unprecedented energy levels. Higher-energy particles are used at the LHC because they can (a) get closer to each other and probe smaller distances. (b) create massive particles front the energy. to) both of the above. 04. The mostfamous physics equation is Einstein's E = tool. (a) Explain what each letter in the equation represents. and what the equation means. (b) Draw a picture of what happens when an electron and a positron are created in a bubble chamber. Where does the mass of the electron and positron come from? Answer: 05. Science was much simpler 30 years ago. Everything appeared to be made of just electron, protons. and neutrons. Then physicists probed deeper into matter and detected new particles. (a) Why was the discovery of new panicles a problem? (b) How was it solved? Answer: | l CIT. The Standard Model describes what is needed to make matter and the forces that hold it together. (a) Fill in the table for the Standard Model. Bosons Generation Gene-Iran on Generration (b) What is special about the rst column? to) How are the next two columns different from the first? (d) How is the last column different from the other three? Answer: Le ptons \fRead 17.2 and 17.3 Pearson and then complete the following ow chart from page 350 of the textbook to connect the most current terminoiogy and ideas that describe Our current understanding of the structure of matter. (15 marks) \fT. Compare the quark composition of a proton to that of a neuu'on. Answer: 3. Destnihe the difference between mesons and baryons in terms of quarks. Answer: 9. Using quark theory, write an equation for the beta decay of a neutron. Show that drarge is conserved in this decay process. Answer: It]. What is missing in the following equation? Justify your answer. Identify each of the particles. _+ is -. odd +115 : 11. Which fundamental force is strongest over large distanc? Which fundamental force is strongest over nuclear distances? ANSWEI': 12. What are No advantages of using units of 1".rle'iu'lc2 to express the mass of subatomic particles? ANSWEI': 13. Desihe an experiment that provided evidence for the existence of quarks. Answer: ANSWEI': 14. Why did physicists suspect that there might be a sixth quark? What is the name of this sixth quark? Wh],r was a huge accelerator necessary for the discovery of this quark? : 15. Determine the charge on a particle having the quark composition uua. Answer: l'ISWEI': 3. The tracks in this bubble chamber diagram show the creatian of two particles. lnitiailjlr the particles have the same speed. Magnetic field is indicated. a. What evidence that a phatcrn created these particles In. Why is it liltelj,r that the interaction invalves an antiparticle c. Haw are the mass and charge of these 2 particles related? d. Which track shows the path of a positive particle? AI'ISWEI