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2.1 Chemical Elements
  • Matter is composed of 92 naturally occurring elements, each composed of atoms.
  • Atoms have subatomic particles: electrons, protons, and neutrons.
  • Atoms of the same type that differ by the number of neutrons are called isotopes.
  • Atoms are characterized by the number of protons and neutrons in a nucleus and the number of electrons in shells about the nucleus.
  1. What six elements make up 98% of an organism's body weight?
    Answer
  2. Briefly describe an atom (what are its components and how are they arranged?).
    Answer
  3. What determines the manner in which atoms react with one another?
    Answer
Essential Study Partner Summaries of major points:
  1. Matter
  2. Atomic structure
  3. Energy levels
Art quizzes Animations
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2.2 Elements and Compounds
  • Atoms react with one another by giving up, gaining, or sharing electrons.
  • Bonding between atoms results in molecules with distinctive chemical properties and shapes.
  • The biological role of a molecule is determined, in part, by its shape.
  1. What is the difference between ionic and covalent bonds?
    Answer
  2. Why is water considered to be a polar molecule?
    Answer
  3. What causes a hydrogen bond and how strong is this bond compared to covalent or ionic bonds?
    Answer
Essential Study Partner Summaries of major points:
  1. Molecules
  2. Ionic bonding
  3. Covalent bonding
  4. Nonpolar and polar covalent bonds
Animations
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2.3 Chemistry of Water
  • The existence of living things is dependent on the chemical and physical characteristics of water.
  • Living things are sensitive to the hydrogen ion concentration [H+] of solutions, which can be indicated using the pH scale.
  1. Why is it important to life that water is capable of absorbing and storing heat?
    Answer
  2. What does it mean that water is cohesive and adhesive and how are these properties important to life?
    Answer
  3. _____________ molecules dissociate in water and release hydrogen (H+) ions, while ____________ molecules dissociate in water and release hydroxide (OH-) ions.
    Answer
  4. A solution with a pH of 9 is __________ times (more or less) basic than a solution of 6.
    Answer
  5. What is the function of buffers in living systems?
    Answer
Essential Study Partner Summaries of major points:
  1. First cells evolved in water
  2. Properties of water
  3. Acids and bases
Art quizzes Study guide





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