BIO-1120: Chapter 2

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BIO-1120: Chapter 2
2014-12-16 11:06:25
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  1. Matter
    anything that takes up space and has mass
  2. Element
    any substance that cannot be broken down to any other substance by chemical reactions
  3. Compound
    a substance consisting of two or more different elements combined in a fixed ratio
  4. Essential Elements
    a chemical element required for an organism to survive, grow, and reproduce
  5. Trace Element
    an element indispensable for life but required in extremely minimal amounts
  6. Atom
    the smallest unit of matter that retains the properties of an element
  7. Neutrons
    a subatomic particle having no electrical charge (electrically neutral), with a mass of about 1.7 x 10-24 g, found in the nucleus of an atom
  8. Protons
    a subatomic particle with a single positive electrical charge, with a mass of about 1.7 x 10-24 g, found in the nucleus of an atom
  9. Electrons
    a subatomic particle with a single negative electrical charge and a mass about 1/2000 that of a neutron or proton; one or more electrons move around the nucleus of an atom
  10. Atomic Nucleus
    an atom's dense central core, containing protons and neutrons
  11. Dalton
    a measure of mass for atoms and subatomic particles; the same as the atomic mass unit, or amu
  12. Atomic Number
    the number of protons in the nucleus of an atomic, unique for each element and designated by a subscript
  13. Mass Number
    the sum of the number of protons and neutrons in an atom's nucleus
  14. Atomic Mass
    the total mass of an atom, numerically equivalent to the mass in grams of 1 mole of the atom; (for an element with more than one isotope, the atomic mass is the average mass of the naturally occurring isotopes weighted by their abundance)
  15. Isotopes
    one of several atomic forms of an element, each with the same number of protons but a different number of neutrons, thus differing in atomic mass
  16. Radioactive Isotope
    an isotope (an atomic form of a chemical element) that is unstable; the nucleus decays spontaneously, giving off detectable particles of energy
  17. Half-Life
    the amount of time it takes for 50% of a sample of a radioactive isotope to decay
  18. Radiometric Dating
    a method for determining the absolute age of rocks and fossils, based on the half-life of radioactive isotopes
  19. Energy
    the capacity to cause change, especially to do work (to move matter against an opposing force)
  20. Potential Energy
    the energy that matter possesses as a result of its location or spatial arrangement (structure)
  21. Electron Shells
    an energy level of electrons at a characteristic average distance from the nucleus of an atom
  22. Valence Electrons
    an electron in the outermost electron shell
  23. Valence Shell
    the outermost energy shell of an atom, containing the valence electrons involve in the chemical reactions of that atom
  24. Orbital
    the three-dimensional space where an electron is found 90% of the time
  25. Chemical Bond
    an attraction between two atoms, resulting from a sharing of outer-shell electrons or the presence of opposite charges on the atoms; the bonded atoms gain complete out electron shells
  26. Molecule
    two or more atoms held together by covalent bonds
  27. Single Bonds
    a single covalent bond; the sharing of a pair of valence electrons by two atoms
  28. Double Bond
    a double covalent bond; the sharing of two pairs of valence electrons by two atoms
  29. Valence
    the bonding capacity of a given atom; usually equals the number of unpaired electrons required to complete the atom's outermost (valance) shell
  30. Electronegativity
    the attraction of a given atom for the electrons of a covalent bond
  31. Nonpolar Covalent Bond
    a type of covalent bond in which electrons are shared equally between two atoms of similar electronegativity
  32. Polar Covalent Bond
    a covalent bond between atoms that differ in electronegativity; the shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive
  33. Ions
    an atom or group of atoms that has gained or lost one or more electrons, thus acquiring a charge
  34. Cation
    a positively charged ion
  35. Anion
    a negatively charged ion
  36. Ionic Bond
    a chemical bond resulting from the attraction between oppositely charged ions
  37. Ionic Compounds
    a compound resulting from the formation of an ionic bond; also called a salt
  38. Hydrogen Bond
    a type of weak chemical bond that is formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule or in another region of the same molecule
  39. Van Der Waals Interactions
    weak attractions between molecules or parts of molecules that result from transient local particle changes
  40. Reactants
    a starting material in a chemical reaction
  41. Product
    a material resulting from a chemical reaction
  42. Chemical Equilibrium
    in a chemical reaction, the state in which the rate of the forward reaction equals the rate of the reverse reaction, so about the relative concentrations of the reactants and products do not change with time