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Chapter 2: Essential chemistry for biology

  1. What is the most common ingredient in the earth's crust?
    Floride
  2. Matter
    Is anything that ocupies space and has mass.

    • -liquid
    • -solid
    • -gas
  3. Elements
    Substances that cannot be broken down into other substances.
  4. # of natural elements found on Earth?
    92
  5. How many elements are essential to life?
    24
  6. What 4 elements make up 96% of our body weight?
    • oxyegen
    • carbon
    • hydrogen
    • nitrogen
  7. Compound
    substances that contain 2 or more elements in a fixed ratio.

    H2O
  8. Proton
    Part of an atom that holds a positive charge.
  9. Electron
    Part of an atom that is negatively charged.
  10. Neutron
    part of an atom that is neutral.
  11. What does a nucleus contain?
    Protons and neutrons
  12. Atomic number
    The number of protons, which determines the element.
  13. Mass number
    The sum of the number of protons and neutorns
  14. Mass
    measure of the amount of matter in an object.
  15. Isotopes
    alternate mass forms of an element.
  16. What has the same number of protons and electrons, but diffrent number of neutrons?
    Isotopes
  17. Radeoactive isotope
    Its nucleus gives off particles of energy.
  18. What determines how an atom behaves when encountering another atom?
    Electrons
  19. The ____ an electron is from the nugleus, the _____ its energy
    • Farther
    • Greater
  20. Number of electrons in the outer most shell determines _______ of an atom.
    The chemical properties
  21. number of electrons in an atoms shell?
    • Two in the intermost shell
    • eight in the second and third shell.
  22. Chemical reactions usually result in atoms?
    • staying close together
    • Being held together by chemical bonds
  23. Ionic bonds
    are formed between oppositely charged ions.
  24. Ions
    Charged atoms
  25. Covalent bond
    Two atoms share one or more pairs of outer-shell electrons.
  26. Molecule
    atoms that are held togehter by covalent bonds.
  27. Polar molecule
    oppostie charges on opposite ends

    (water)
  28. The polarity of water results in ___ electrical attractions between neighboring water molecules.
    Weak
  29. Chemical reactions
    breaking existing chemical bonds and forming new ones.
  30. Chemical reactions include
    reactants and products
  31. Reactant
    The starting materials
  32. Products
    The end materials
  33. What can chemical reactions not do?
    Create or destroy matter.
  34. Your cells are composed of __% - ___% water
    70-90
  35. Evaporative cooling
    Removes heat from the earth and from organisms.
  36. Solution
    liquid consisting of homogeneous mixtures of two or more substances.
  37. Solvent
    the dissolving agent
  38. Solute
    The dessolved substance
  39. Aqueous solution
    when wate is the solvent.

    (Tea)
  40. Acid
    a chemical compound that releases H+ to a solution
  41. Base
    a compound that accepts H+ and removes it from the solution
  42. pH scale
    describes the acidity of a solution
  43. Buffers
    Substances that resist pH change
  44. What do buffers do?
    • accpet H+ ions when they are in exess
    • Donate H+ ions when they are depleted
Author
Ayafox
ID
168481
Card Set
Chapter 2: Essential chemistry for biology
Description
Essential chemistry for biology from campbell's essential biology, chapter two
Updated

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