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Download Linking Asteroids and Meteorites through Reflectance Spectroscopy
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Conversations with the Earth Tom Burbine [email protected] Chemistry • The science of matter and the changes it undergoes. Atoms • • • • • Atoms are made up of 3 types of particles Protons – positive charge (+1) Electrons – negative charge (-1) Neutrons – neutral charge (no charge) Protons and Neutrons are found in the nucleus Elements • Different elements have different numbers of protons • The properties of an atom are a function of the electrical charge of its nucleus Definitions • Atomic Number – Number of protons • Atomic Mass – Number of protons and neutrons • U235 – atomic mass 92- atomic number • Isotopes – Same number of protons but different numbers of neutrons • http://www.youtube.com/watch?v=GFIvXVMbII0 • http://www.chemicalelements.com/ • http://www.periodicvideos.com/ Periodic Table • A chart in which all known elements are listed in order of atomic number • http://theodoregray.com/periodictable/ • http://cosmiclog.msnbc.msn.com/_news/2011/01/ 26/5925968-see-the-worlds-smallest-periodictable • Period – Horizontal row • Across any period, the properties of elements change • Group – Vertical column • Down any group, the properties of elements are very similar Radioactivity • Radioactivity – decay of an atomic nucleus • All elements with an atomic number greater than 82 (lead) are radioactive Bohr’s Planetary Model • Electrons orbit the nucleus in specific energy levels • Level n=1 is closest to nucleus • Level n=2 is second closest Shell Model • Electrons behave as they are arranged in a series of concentric shells around the nucleus • Innermost shell can contain 2 electrons • The second and third shells can contain 8 electrons each • The fourth and fifth shells can contain 18 electrons each • Valence electrons are the electrons in the outermost shell • These electrons participate in chemical bonding Ion • Ion – an electrically charged particle created when an atom either loses or gains one or more electrons Ionic Bond • Ionic bond – chemical bond in which an attractive electric force holds an opposite charge together Covalent Bond • Covalent bond – a chemical bond in which atoms are held by their mutual attraction for two or more electrons share • Molecules are held together by covalent chemical bonds Metallic Bonds • Atoms "share" electrons that float about in a general electron cloud Charges need to balance • Na ions carry a +1 charge • Cl ions carry a -1 charge • Na+ + Cl- → NaCl (Sodium chloride) • HCl – Hydrogen Chloride • Li2O – Lithium Oxide • CO – Carbon Monoxide • CO2 – Carbon Dioxide • http://www.hulu.com/watch/63320/cosmos-thelives-of-the-stars#s-p1-so-i0 Any Questions?
