Physics and Chemistry Foundations - LBCC e-Learning Zone
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Physics and Chemistry Foundations Dr. Mike MacCallum Long Beach City College mmaccallum@lbcc.edu Astronomy Picture of the Day ✤ http://apod.nasa.gov/apod/ Astronomer of the Week ✤ Miguel Castro-Colin ✤ Assistant Professor ✤ Department of Physics ✤ Max Planck Institute, Germany ✤ Research interest: X-ray diffraction ✤ http://www.mf.mpg.de/en/abteilungen/dosch/secretary/staff/castrocolin.shtml News of the Week ✤ ✤ Astronomy News of the Week ✤ http://www.lbcc.edu/Astronomy/News.cfm The sky this week ✤ http://www.starhustler.com/JHSG_DNLD.html Student Success Tip of the Week ✤ Take those basic skills classes first! ✤ Now that you have taken the Assessment Exam… ✤ Be sure to start your basic skills class(es) right away ✤ English 801A --> 801B --> 105 --> 1 ✤ Reading 880 --> 881 --> 882 --> 883 --> 82 ✤ Math 805 --> 815 --> 110 (or 110A/B) --> 130 (or 130A/B) Questions from Last Week A Brief History of Astronomy Lecture Physics and Chemistry Foundations James Clerk Maxwell 1831-1879 ✤ ✤ ✤ ✤ ✤ Developed the classical electromagnetic field equations Explained all previous experiments and data of optics, electricity, and magnetism Showed that light and electric and magnetic fields travel as waves His equations included the speed of light as a constant The second great unification of physics, after Newton ✤ http://www-history.mcs.st-and.ac.uk/Biographies/Maxwell.html Albert Einstein 1879-1955 ✤ ✤ ✤ Most famous for his Special and General Theories of Relativity Published over 300 papers Won the Nobel Prize for the discovery of the law of the photoelectric effect ✤ Laid the foundation for the understanding of particles of light, called photons ✤ http://www-history.mcs.st-andrews.ac.uk/Biographies/Einstein.html Max Planck 1858-1947 ✤ ✤ ✤ One of the founders of the quantum theory of light Developed the theory that light travels in discrete bundles of energy Also showed that the energy radiated by a body was curved in nature with a peak associated with the temperature of the body ✤ http://en.wikipedia.org/wiki/Wien%27s_displacement_law Structure of the Atom ✤ J.J. Thomson ✤ Plum pudding model ✤ http://library.thinkquest.org/28582/history/plum.htm Ernest Rutherford 1871-1937 ✤ ✤ His famous gold foil experiment ✤ Only about 1 in 8,000 particles were reflected ✤ Conclusion: atoms are mostly empty space ✤ Almost all the mass of an atom is concentrated in nucleus ✤ http://www.phrenopolis.com/perspective/atom/ Won the Noble Prize for this work ✤ http://www.rsc.org/chemsoc/timeline//pages/1911.html Structure of the Atom ✤ ✤ Atomic model ✤ http://www.purchon.com/chemistry/atoms.htm ✤ http://education.jlab.org/qa/atom_model.html Energy levels ✤ ✤ ✤ http://www.worsleyschool.net/science/files/electronphoton/interaction.html http://cas.sdss.org/dr7/en/proj/advanced/spectraltypes/energylevels.asp Spectra ✤ http://en.wikipedia.org/wiki/Hydrogen_spectral_series Photon ✤ ✤ ✤ ✤ A photon is a quanta of electromagnetic radiation Is it a particle or a wave? ✤ Yes! It depends on the observation being made ✤ Heisenberg’s uncertainty principle: ✤ We can know its position (particle) ✤ We can know its momentum (wave) ✤ We cannot know both at the same time Zero rest mass Travels at the speed of light The Electromagnetic Spectrum ✤ ✤ ✤ ✤ http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html http://imagine.gsfc.nasa.gov/docs/science/know_l2/emspectrum.html http://mc2.gulf-pixels.com/?p=281 http://www.ntia.doc.gov/osmhome/allochrt.pdf Periodic Table of Elements ✤ ✤ http://www.ptable.com/ http://www.webelements.com/ ✤ Hydrogen (H) ✤ Atomic number = 1, Atomic weight = 1.00794 ✤ One proton and one electron ✤ Note: 1.00794 x 4 = 4.03176 ✤ Helium (He) ✤ Atomic number = 2, Atomic weight = 4.002602 ✤ Two protons, two neutrons, and two electrons Periodic Table of Elements ✤ ✤ Iron (Fe) ✤ Atomic number = 26, Atomic weight = 55.845 ✤ 26 protons, 30 neutrons and 26 electrons The spectra of the elements ✤ http://jersey.uoregon.edu/vlab/elements/Elements.html Brownian Motion ✤ Random motion of a small particle, due to atoms ✤ ✤ ✤ http://galileoandeinstein.physics.virginia.edu/more_stuff/Applets/brownian/brownian.html Atoms jiggle The more energy, the more they jiggle ✤ Solid ✤ Liquid ✤ Gas ✤ Plasma Plasma ✤ ✤ ✤ The fourth state of matter The most common state of matter ✤ A mixture of free electrons and positively ionized particles ✤ Energy must be present to strip the electrons from the atoms ✤ In space, usually ultraviolet light ✤ If the energy stops, the electrons and ions will recombine and return to normal matter Found in the center of stars and in emission nebulae ✤ http://en.wikipedia.org/wiki/Plasma_(physics) Ionization ✤ Loss of one or more electrons ✤ Hydrogen ✤ H or H 0 = Molecular hydrogen 2 ✤ H or H I = Normal hydrogen ✤ H+ or H II = Ionized hydrogen ✤ Iron ✤ Fe or Fe I = Normal iron ✤ Fe+ or Fe II = Singly ionized iron ✤ Fe++ or Fe III = Doubly ionized iron ✤ Fe+++ or Fe IV = Triply ionized iron Conservation of Energy ✤ ✤ ✤ In any closed system, energy must be conserved ✤ Energy be neither created nor destroyed ✤ Matter can be converted to energy according to E = mc2 Particle physics ✤ Discovery of the neutrino In astronomy ✤ Orbital mechanics ✤ Angular momentum ✤ Magnetic fields around the sun ✤ Magnetic fields around pulsars and black holes ✤ http://library.thinkquest.org/2745/data/lawce1.htm Law of Entropy ✤ ✤ All systems tend to become more orderly--reach a lower energy state ✤ A pail of hot and a pail of cold water ✤ A brand new car ✤ Stars and galaxies Is the basis of the time arrow of the universe ✤ http://entropysite.oxy.edu/students_approach.html Four Fundamental Forces ✤ ✤ The Electromagnetic Force ✤ Electromagnetic radiation ✤ Magnetism ✤ Transmitted by photons The Strong Force ✤ At the level of atomic nuclei ✤ Binds protons, neutrons, and quarks ✤ Transmitted by gluons ✤ http://en.wikipedia.org/wiki/Strong_interaction Four Fundamental Forces ✤ ✤ The Weak Force ✤ Responsible for radioactive, beta decay ✤ Emission of an electron by a neutron or a positron by a proton ✤ Transmitted by W and Z bosons ✤ http://en.wikipedia.org/wiki/Weak_interaction The Gravitational Force ✤ The weakest of all the forces ✤ The least understood ✤ Newton: A force related to the mass of an object ✤ Einstein: A curvature of space time Next Week: The Earth and Its Moon ✤ ✤ ✤ ✤ ✤ ✤ ✤ ✤ ✤ The age, formation, and composition of the earth Plate tectonics The atmosphere and the magnetosphere The day and the seasons Atmospheric phenomena How the moon was formed The distance from the earth to the moon Conditions on the lunar surface Phases of the moon, eclipses, and tides Some Things to Think About ✤ ✤ ✤ ✤ ✤ ✤ ✤ How do we know how old the earth is? How do we measure a day? Do they ever have a white Christmas in Australia? Why doesn’t the earth have craters like the moon? Which planet in the solar system has the largest moon, in comparison to the size of the planet? What is the density of the moon compared to the earth? Why? Will we ever return to the moon? See you Next Week!!
