Lecture0510fa - Chemistry 83 Origin and Properties of the...

Info icon This preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
Chemistry 83 09/08/09 1 Origin and Properties of the Chemical Elements The study of the origin, evolution and ultimate fate of the universe is part of the discipline of cosmology Kaiser, D. The Other Evolution Wars. American Scientist. 95. 520 Albert Einstein and Georges Lemaitre Lemaitre (1927) extended work of Einstein (1905), E = mc 2 . Church saw no conflict between religion and Big Bang hypothesis. He was appointed to bishop, later to head of the Pontifical Academy of Science at the Vatican, and finally to monsignor. “Big Bang” hypothesis was proposed by a Catholic priest
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Chemistry 83 09/08/09 2 Origin of Universe: Big Bang Theory Big Bang (12 - 14 B years ago) - all matter and energy were at a point, then an explosion occurred followed by a continuous expansion Theory based on observation by Hubble that the Universe is expanding Validity unknown as with all theories • Utility – Explains expansion of Universe – Correctly predicted residual heat in Universe ~3 K (0 K = -273 o C = -459 o F) – Explains origin of the chemical elements Overview of the Origin of the Chemical Elements Big Bang 10 30 K 3 min 300,000-500000 yr Stars and Galaxies Nucleosynthesis - fusion in smaller stars for elements having Z 26, and neutron capture for elements having Z > 26 but only when stars >1.4 times greater in mass than our sun undergo a supernova H + , He 2+ ,e - 10 6 K (plasma) H, He 10 3 K (atoms) 12-13 billion yrs n + p + ; n p + + e - 10 12 K 10 -3 sec 1 billion yrs gravity Fusion reactions during Big Bang E = mc 2
Image of page 2
Chemistry 83 09/08/09 3 H and He nuclides (nuclei) were formed during the Big Bang During the Big Bang, energy converted to mass, E = mc 2 , where E is energy, m is mass of particles created, and c is velocity of light Particles formed were p, n, and e in a plasma Reactions were limited since n decay rapidly, n p + e, and temperature quickly fell below that needed for nuclear reactions to occur Some n and p reacted to form H-2, He-3, He-4 nuclides, but atoms could not form at that high T http://www.plasmas.org/E-4phases2.jpg Fourth State of Matter - Plasma http://www.ipp.mpg.de/BB/Kernfusion/fig5.gif Heat Cool
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Chemistry 83 09/08/09 4 Nuclear changes are represented symbolically by nuclear equations M where Y is symbol for particle, C is charge, M is mass Alpha α Proton p or H-1 Deuteron D or H-2 Electron β - or e - Positron β + or e + Neutron n Name Symbol Other Nuclei of atoms (nuclides): Z X, Other particles: C Y, A Writing a Nuclear Equation First write the skeleton equation - translation of a fact into symbols Fact : protons combine at high temperature to produce H-2 and a positron.
Image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern