Transcript Linking Asteroids and Meteorites through Reflectance

Conversations with the Earth
Tom Burbine
[email protected]
Chemistry
• The science of matter and the changes it
undergoes.
Atoms
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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?