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28 Cards in this Set
- Front
- Back
Chemical Evolution
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Simple chemical compounds in the atmosphere and ocean form more complex substances.
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Condensation theory
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Young planets should be surrounded by dust
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Nucleus
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Made up of protons and neutrons
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elections
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orbit around the nucleus, negatively charged
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Elements
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contain a specific number of protons
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Isotypes
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Same number of protons, different number of electrons
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Mass number
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Sum of protons and neutrons: measured in amu (atomic mass unit-dalton)
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Radioactive isotope
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Nuclei tend to change spontaneously by emitting radiation or a particle (radioactive decay)
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Half-life
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The time it takes for half of the parent isotope to decay to a particular daughter isotope
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Four main atoms:
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Hydrogen, carbon, nitrogen, and oxygen
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Atomic number
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Number of protons; subscript
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Mass number
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Number of protons and neutrons, superscript
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Valence shell
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Outershell of an atom
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Valence
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The number of unpaired electrons found in an atom
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Covalent bonds
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Atoms held together by shared electrons.
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Molecules
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Substances held together by covalent bonds
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Nonpolar covalent bond
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A covalent bond that is symmetrical(equal sharring of electrons)
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Polar covalent bonds
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Asymmetric sharing of electrons
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Electronegativity
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the tendency of an atom to attract electrons towards itself
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Ionic bonds
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Electrons are completely transferred from one atom to the other
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Ion
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Atom/molecule that is charged
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Cation
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Positively charged ion
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Anion
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Negatively charged ion
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Methane
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CH4
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Water
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H2O
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Sodium Chloride
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NACL
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Mole
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6.022x10^23; the mass of one mole of any molecule is the same as its molecular weight expressed in grams.
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Molarity
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The number of moles per liter of solution
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